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<meta name="description" content="Task You need to create a Sum class which will sum integers from command line arguments and output the sum to console.
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Examples:
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java Sum 1 2 3 Expected output: 6.
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java Sum 1 2 -3 Expected output: 0." /><link rel="canonical" href="http://localhost:1313/courses/prog-intro/homeworks/sum/" itemprop="url" />
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Learn Java programming
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<meta itemprop="description" content="Task You need to create a Sum class which will sum integers from command line arguments and output the sum to console.
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Examples:
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java Sum 1 2 3 Expected output: 6.
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java Sum 1 2 -3 Expected output: 0.">
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Examples:
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java Sum 1 2 3 Expected output: 6.
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java Sum 1 2 -3 Expected output: 0.">
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<div>
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hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
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>Courses
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<span class="hextra-sidebar-collapsible-button"><svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="hx:h-[18px] hx:min-w-[18px] hx:rounded-xs hx:p-0.5 hx:hover:bg-gray-800/5 hx:dark:hover:bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="hx:origin-center hx:transition-transform hx:rtl:-rotate-180"></path></svg></span>
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</a><div class="hx:ltr:pr-0 hx:overflow-hidden">
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<ul class='hx:relative hx:flex hx:flex-col hx:gap-1 hx:before:absolute hx:before:inset-y-1 hx:before:w-px hx:before:bg-gray-200 hx:before:content-[""] hx:ltr:ml-3 hx:ltr:pl-3 hx:ltr:before:left-0 hx:rtl:mr-3 hx:rtl:pr-3 hx:rtl:before:right-0 hx:dark:before:bg-neutral-800'><li class="hx:flex hx:flex-col "><a
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class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
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hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
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href="/courses/spring-boot/"
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>Spring Boot
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</a>
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</li><li class="hx:flex hx:flex-col open"><a
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class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
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hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
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href="/courses/prog-intro/"
|
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|
||
>Introduction to Programming in Java
|
||
<span class="hextra-sidebar-collapsible-button"><svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="hx:h-[18px] hx:min-w-[18px] hx:rounded-xs hx:p-0.5 hx:hover:bg-gray-800/5 hx:dark:hover:bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="hx:origin-center hx:transition-transform hx:rtl:-rotate-180"></path></svg></span>
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</a>
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<div class="hx:ltr:pr-0 hx:overflow-hidden">
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<ul class='hx:relative hx:flex hx:flex-col hx:gap-1 hx:before:absolute hx:before:inset-y-1 hx:before:w-px hx:before:bg-gray-200 hx:before:content-[""] hx:ltr:ml-3 hx:ltr:pl-3 hx:ltr:before:left-0 hx:rtl:mr-3 hx:rtl:pr-3 hx:rtl:before:right-0 hx:dark:before:bg-neutral-800'><li class="hx:flex hx:flex-col open"><a
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class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
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hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/"
|
||
|
||
>Homeworks
|
||
<span class="hextra-sidebar-collapsible-button"><svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="hx:h-[18px] hx:min-w-[18px] hx:rounded-xs hx:p-0.5 hx:hover:bg-gray-800/5 hx:dark:hover:bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="hx:origin-center hx:transition-transform hx:rtl:-rotate-180"></path></svg></span>
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</a>
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<div class="hx:ltr:pr-0 hx:overflow-hidden">
|
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<ul class='hx:relative hx:flex hx:flex-col hx:gap-1 hx:before:absolute hx:before:inset-y-1 hx:before:w-px hx:before:bg-gray-200 hx:before:content-[""] hx:ltr:ml-3 hx:ltr:pl-3 hx:ltr:before:left-0 hx:rtl:mr-3 hx:rtl:pr-3 hx:rtl:before:right-0 hx:dark:before:bg-neutral-800'><li class="hx:flex hx:flex-col open"><a
|
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class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
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hextra-sidebar-active-item hx:bg-primary-100 hx:font-semibold hx:text-primary-800 hx:contrast-more:border hx:contrast-more:border-primary-500 hx:dark:bg-primary-400/10 hx:dark:text-primary-600 hx:contrast-more:dark:border-primary-500"
|
||
href="/courses/prog-intro/homeworks/sum/"
|
||
|
||
>Sum
|
||
<span class="hextra-sidebar-collapsible-button"><svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="hx:h-[18px] hx:min-w-[18px] hx:rounded-xs hx:p-0.5 hx:hover:bg-gray-800/5 hx:dark:hover:bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="hx:origin-center hx:transition-transform hx:rtl:-rotate-180"></path></svg></span>
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</a>
|
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|
||
<ul class='hx:flex hx:flex-col hx:gap-1 hx:relative hx:before:absolute hx:before:inset-y-1 hx:before:w-px hx:before:bg-gray-200 hx:before:content-[""] hx:dark:before:bg-neutral-800 hx:ltr:pl-3 hx:ltr:before:left-0 hx:rtl:pr-3 hx:rtl:before:right-0 hx:ltr:ml-3 hx:rtl:mr-3'><li>
|
||
<a
|
||
href="#solution"
|
||
class="hx:flex hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [word-break:break-word] hx:cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] hx:contrast-more:border hx:gap-2 hx:before:opacity-25 hx:before:content-['#'] hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:text-gray-900 hx:contrast-more:dark:text-gray-50 hx:contrast-more:border-transparent hx:contrast-more:hover:border-gray-900 hx:contrast-more:dark:hover:border-gray-50"
|
||
>Solution</a>
|
||
</li>
|
||
</ul>
|
||
|
||
<div class="hx:ltr:pr-0 hx:overflow-hidden">
|
||
<ul class='hx:relative hx:flex hx:flex-col hx:gap-1 hx:before:absolute hx:before:inset-y-1 hx:before:w-px hx:before:bg-gray-200 hx:before:content-[""] hx:ltr:ml-3 hx:ltr:pl-3 hx:ltr:before:left-0 hx:rtl:mr-3 hx:rtl:pr-3 hx:rtl:before:right-0 hx:dark:before:bg-neutral-800'><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/sum/sumbigdecimalhex/"
|
||
|
||
>SumBigDecimalHex
|
||
</a>
|
||
|
||
</li><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/sum/sumbigintegeroctal/"
|
||
|
||
>SumBigIntegerOctal
|
||
</a>
|
||
|
||
</li><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/sum/sumdouble/"
|
||
|
||
>SumDouble
|
||
</a>
|
||
|
||
</li><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/sum/sumdoublehex/"
|
||
|
||
>SumDoubleHex
|
||
</a>
|
||
|
||
</li><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/sum/sumhex/"
|
||
|
||
>SumHex
|
||
</a>
|
||
|
||
</li><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/sum/sumlongoctal/"
|
||
|
||
>SumLongOctal
|
||
</a>
|
||
|
||
</li><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/sum/conclusion/"
|
||
|
||
>Summing Up
|
||
</a>
|
||
|
||
</li></ul>
|
||
</div>
|
||
</li></ul>
|
||
</div>
|
||
</li><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/lectures/"
|
||
|
||
>Lectures
|
||
<span class="hextra-sidebar-collapsible-button"><svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="hx:h-[18px] hx:min-w-[18px] hx:rounded-xs hx:p-0.5 hx:hover:bg-gray-800/5 hx:dark:hover:bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="hx:origin-center hx:transition-transform hx:rtl:-rotate-180"></path></svg></span>
|
||
</a>
|
||
<div class="hx:ltr:pr-0 hx:overflow-hidden">
|
||
<ul class='hx:relative hx:flex hx:flex-col hx:gap-1 hx:before:absolute hx:before:inset-y-1 hx:before:w-px hx:before:bg-gray-200 hx:before:content-[""] hx:ltr:ml-3 hx:ltr:pl-3 hx:ltr:before:left-0 hx:rtl:mr-3 hx:rtl:pr-3 hx:rtl:before:right-0 hx:dark:before:bg-neutral-800'><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/lectures/intro/intro/"
|
||
|
||
>Lecture 1. Introduction
|
||
</a>
|
||
|
||
</li></ul>
|
||
</div>
|
||
</li></ul>
|
||
</div>
|
||
</li><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/paradigms/"
|
||
|
||
>Paradgims of Programming
|
||
</a>
|
||
|
||
</li></ul>
|
||
</div></li>
|
||
</ul>
|
||
|
||
<ul class="hx:flex hx:flex-col hx:gap-1 hx:max-md:hidden">
|
||
|
||
<li class=""><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/spring-boot/"
|
||
|
||
>Spring Boot
|
||
</a></li>
|
||
<li class="open"><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/"
|
||
|
||
>Introduction to Programming in Java
|
||
<span class="hextra-sidebar-collapsible-button"><svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="hx:h-[18px] hx:min-w-[18px] hx:rounded-xs hx:p-0.5 hx:hover:bg-gray-800/5 hx:dark:hover:bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="hx:origin-center hx:transition-transform hx:rtl:-rotate-180"></path></svg></span>
|
||
</a><div class="hx:ltr:pr-0 hx:overflow-hidden">
|
||
<ul class='hx:relative hx:flex hx:flex-col hx:gap-1 hx:before:absolute hx:before:inset-y-1 hx:before:w-px hx:before:bg-gray-200 hx:before:content-[""] hx:ltr:ml-3 hx:ltr:pl-3 hx:ltr:before:left-0 hx:rtl:mr-3 hx:rtl:pr-3 hx:rtl:before:right-0 hx:dark:before:bg-neutral-800'><li class="hx:flex hx:flex-col open"><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/"
|
||
|
||
>Homeworks
|
||
<span class="hextra-sidebar-collapsible-button"><svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="hx:h-[18px] hx:min-w-[18px] hx:rounded-xs hx:p-0.5 hx:hover:bg-gray-800/5 hx:dark:hover:bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="hx:origin-center hx:transition-transform hx:rtl:-rotate-180"></path></svg></span>
|
||
</a>
|
||
<div class="hx:ltr:pr-0 hx:overflow-hidden">
|
||
<ul class='hx:relative hx:flex hx:flex-col hx:gap-1 hx:before:absolute hx:before:inset-y-1 hx:before:w-px hx:before:bg-gray-200 hx:before:content-[""] hx:ltr:ml-3 hx:ltr:pl-3 hx:ltr:before:left-0 hx:rtl:mr-3 hx:rtl:pr-3 hx:rtl:before:right-0 hx:dark:before:bg-neutral-800'><li class="hx:flex hx:flex-col open"><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hextra-sidebar-active-item hx:bg-primary-100 hx:font-semibold hx:text-primary-800 hx:contrast-more:border hx:contrast-more:border-primary-500 hx:dark:bg-primary-400/10 hx:dark:text-primary-600 hx:contrast-more:dark:border-primary-500"
|
||
href="/courses/prog-intro/homeworks/sum/"
|
||
|
||
>Sum
|
||
<span class="hextra-sidebar-collapsible-button"><svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="hx:h-[18px] hx:min-w-[18px] hx:rounded-xs hx:p-0.5 hx:hover:bg-gray-800/5 hx:dark:hover:bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="hx:origin-center hx:transition-transform hx:rtl:-rotate-180"></path></svg></span>
|
||
</a>
|
||
<div class="hx:ltr:pr-0 hx:overflow-hidden">
|
||
<ul class='hx:relative hx:flex hx:flex-col hx:gap-1 hx:before:absolute hx:before:inset-y-1 hx:before:w-px hx:before:bg-gray-200 hx:before:content-[""] hx:ltr:ml-3 hx:ltr:pl-3 hx:ltr:before:left-0 hx:rtl:mr-3 hx:rtl:pr-3 hx:rtl:before:right-0 hx:dark:before:bg-neutral-800'><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/sum/sumbigdecimalhex/"
|
||
|
||
>SumBigDecimalHex
|
||
</a>
|
||
|
||
</li><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/sum/sumbigintegeroctal/"
|
||
|
||
>SumBigIntegerOctal
|
||
</a>
|
||
|
||
</li><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/sum/sumdouble/"
|
||
|
||
>SumDouble
|
||
</a>
|
||
|
||
</li><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/sum/sumdoublehex/"
|
||
|
||
>SumDoubleHex
|
||
</a>
|
||
|
||
</li><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/sum/sumhex/"
|
||
|
||
>SumHex
|
||
</a>
|
||
|
||
</li><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/sum/sumlongoctal/"
|
||
|
||
>SumLongOctal
|
||
</a>
|
||
|
||
</li><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/homeworks/sum/conclusion/"
|
||
|
||
>Summing Up
|
||
</a>
|
||
|
||
</li></ul>
|
||
</div>
|
||
</li></ul>
|
||
</div>
|
||
</li><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/lectures/"
|
||
|
||
>Lectures
|
||
<span class="hextra-sidebar-collapsible-button"><svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="hx:h-[18px] hx:min-w-[18px] hx:rounded-xs hx:p-0.5 hx:hover:bg-gray-800/5 hx:dark:hover:bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="hx:origin-center hx:transition-transform hx:rtl:-rotate-180"></path></svg></span>
|
||
</a>
|
||
<div class="hx:ltr:pr-0 hx:overflow-hidden">
|
||
<ul class='hx:relative hx:flex hx:flex-col hx:gap-1 hx:before:absolute hx:before:inset-y-1 hx:before:w-px hx:before:bg-gray-200 hx:before:content-[""] hx:ltr:ml-3 hx:ltr:pl-3 hx:ltr:before:left-0 hx:rtl:mr-3 hx:rtl:pr-3 hx:rtl:before:right-0 hx:dark:before:bg-neutral-800'><li class="hx:flex hx:flex-col "><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/prog-intro/lectures/intro/intro/"
|
||
|
||
>Lecture 1. Introduction
|
||
</a>
|
||
|
||
</li></ul>
|
||
</div>
|
||
</li></ul>
|
||
</div></li>
|
||
<li class=""><a
|
||
class="hx:flex hx:items-center hx:justify-between hx:gap-2 hx:cursor-pointer hx:rounded-sm hx:px-2 hx:py-1.5 hx:text-sm hx:transition-colors [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] [word-break:break-word]
|
||
hx:text-gray-500 hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:contrast-more:border hx:contrast-more:border-transparent hx:contrast-more:text-gray-900 hx:contrast-more:hover:border-gray-900 hx:dark:text-neutral-400 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:contrast-more:dark:text-gray-50 hx:contrast-more:dark:hover:border-gray-50"
|
||
href="/courses/paradigms/"
|
||
|
||
>Paradgims of Programming
|
||
</a></li>
|
||
|
||
</ul>
|
||
</div>
|
||
|
||
|
||
<div class=" hx:sticky hx:bottom-0 hx:max-h-(--menu-height) hx:bg-white hx:dark:bg-dark hx:mx-4 hx:py-4 hx:shadow-[0_-12px_16px_#fff] hx:flex hx:items-center hx:gap-2 hx:border-gray-200 hx:dark:border-neutral-800 hx:dark:shadow-[0_-12px_16px_#111] hx:contrast-more:border-neutral-400 hx:contrast-more:shadow-none hx:contrast-more:dark:shadow-none hx:border-t" data-toggle-animation="show"><div class="hx:flex hx:grow hx:flex-col"><div class="hx:flex hx:justify-items-start hx:group" data-theme="light">
|
||
<button
|
||
title="Change theme"
|
||
data-state="closed"
|
||
data-location="bottom"
|
||
class="hextra-theme-toggle hx:cursor-pointer hx:rounded-md hx:text-left hx:font-medium hx:h-7 hx:px-2 hx:text-xs hx:hover:bg-gray-100 hx:hover:text-gray-900 hx:dark:hover:bg-primary-100/5 hx:dark:hover:text-gray-50 hx:font-medium hx:text-gray-600 hx:transition-colors hx:dark:text-gray-400 hx:grow"
|
||
type="button"
|
||
aria-label="Change theme"
|
||
>
|
||
<div class="hx:flex hx:items-center hx:gap-2 hx:capitalize"><svg height=12 class="hx:group-data-[theme=dark]:hidden hx:group-data-[theme=system]:hidden" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" d="M12 3v1m0 16v1m9-9h-1M4 12H3m15.364 6.364l-.707-.707M6.343 6.343l-.707-.707m12.728 0l-.707.707M6.343 17.657l-.707.707M16 12a4 4 0 11-8 0 4 4 0 018 0z"/></svg><span class="hx:group-data-[theme=dark]:hidden hx:group-data-[theme=system]:hidden">Light</span><svg height=12 class="hx:group-data-[theme=light]:hidden hx:group-data-[theme=system]:hidden" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" d="M20.354 15.354A9 9 0 018.646 3.646 9.003 9.003 0 0012 21a9.003 9.003 0 008.354-5.646z"/></svg><span class="hx:group-data-[theme=light]:hidden hx:group-data-[theme=system]:hidden">Dark</span><svg height=12 class="hx:group-data-[theme=dark]:hidden hx:group-data-[theme=light]:hidden" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="currentColor">
|
||
<path d="M 11.996094,2 C 6.4986225,2.0192368 2.03125,6.5024993 2.03125,12 c 0,5.497501 4.4673725,9.980763 9.964844,10 H 12 12.0039 c 5.497471,-0.01924 9.964844,-4.502499 9.964844,-10 0,-5.4975007 -4.467373,-9.9807632 -9.964844,-10 H 12 Z M 12,4 c 4.417218,0.017598 7.96875,3.5822356 7.96875,8 0,4.417764 -3.551532,7.982402 -7.96875,8 z" />
|
||
</svg>
|
||
<span class="hx:group-data-[theme=dark]:hidden hx:group-data-[theme=light]:hidden">System</span></div>
|
||
</button>
|
||
<ul
|
||
class="hextra-theme-toggle-options hx:hidden hx:z-20 hx:max-h-64 hx:overflow-auto hx:rounded-md hx:ring-1 hx:ring-black/5 hx:bg-white hx:py-1 hx:text-sm hx:shadow-lg hx:dark:ring-white/20 hx:dark:bg-neutral-800"
|
||
style="position: fixed; inset: auto auto 0px 0px; margin: 0px; min-width: 100px;"
|
||
data-theme="light"
|
||
>
|
||
<li class="hx:flex hx:flex-col">
|
||
<p
|
||
data-item="light"
|
||
class="hx:text-gray-800 hx:dark:text-gray-100 hx:hover:bg-primary-50 hx:hover:text-primary-600 hx:hover:dark:bg-primary-500/10 hx:hover:dark:text-primary-600 hx:relative hx:cursor-pointer hx:whitespace-nowrap hx:py-1.5 hx:transition-colors hx:ltr:pl-3 hx:ltr:pr-9 hx:rtl:pr-3 hx:rtl:pl-9"
|
||
>
|
||
Light
|
||
<span class="hx:absolute hx:inset-y-0 hx:flex hx:items-center hx:ltr:right-3 hx:rtl:left-3 hx:group-data-[theme=dark]:hidden hx:group-data-[theme=system]:hidden"><svg height=1em width=1em xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" d="M5 13l4 4L19 7"/></svg></span>
|
||
</p>
|
||
</li>
|
||
<li class="hx:flex hx:flex-col">
|
||
<p
|
||
data-item="dark"
|
||
class="hx:text-gray-800 hx:dark:text-gray-100 hx:hover:bg-primary-50 hx:hover:text-primary-600 hx:hover:dark:bg-primary-500/10 hx:hover:dark:text-primary-600 hx:relative hx:cursor-pointer hx:whitespace-nowrap hx:py-1.5 hx:transition-colors hx:ltr:pl-3 hx:ltr:pr-9 hx:rtl:pr-3 hx:rtl:pl-9"
|
||
>
|
||
Dark
|
||
<span class="hx:absolute hx:inset-y-0 hx:flex hx:items-center hx:ltr:right-3 hx:rtl:left-3 hx:group-data-[theme=light]:hidden hx:group-data-[theme=system]:hidden"><svg height=1em width=1em xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" d="M5 13l4 4L19 7"/></svg></span>
|
||
</p>
|
||
</li>
|
||
<li class="hx:flex hx:flex-col">
|
||
<p
|
||
data-item="system"
|
||
class="hx:text-gray-800 hx:dark:text-gray-100 hx:hover:bg-primary-50 hx:hover:text-primary-600 hx:hover:dark:bg-primary-500/10 hx:hover:dark:text-primary-600 hx:relative hx:cursor-pointer hx:whitespace-nowrap hx:py-1.5 hx:transition-colors hx:ltr:pl-3 hx:ltr:pr-9 hx:rtl:pr-3 hx:rtl:pl-9"
|
||
>
|
||
System
|
||
<span class="hx:absolute hx:inset-y-0 hx:flex hx:items-center hx:ltr:right-3 hx:rtl:left-3 hx:group-data-[theme=dark]:hidden hx:group-data-[theme=light]:hidden"><svg height=1em width=1em xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" d="M5 13l4 4L19 7"/></svg></span>
|
||
</p>
|
||
</li>
|
||
</ul>
|
||
</div></div></div></aside>
|
||
|
||
<nav class="hextra-toc hx:order-last hx:hidden hx:w-64 hx:shrink-0 hx:xl:block hx:print:hidden hx:px-4" aria-label="table of contents">
|
||
<div class="hextra-scrollbar hx:sticky hx:top-16 hx:overflow-y-auto hx:pr-4 hx:pt-6 hx:text-sm [hyphens:auto] hx:max-h-[calc(100vh-var(--navbar-height)-env(safe-area-inset-bottom))] hx:ltr:-mr-4 hx:rtl:-ml-4"><p class="hx:mb-4 hx:font-semibold hx:tracking-tight">On this page</p><ul>
|
||
<li class="hx:my-2 hx:scroll-my-6 hx:scroll-py-6">
|
||
<a class="hx:font-medium hx:inline-block hx:text-gray-500 hx:hover:text-gray-900 hx:dark:text-gray-400 hx:dark:hover:text-gray-300 hx:contrast-more:text-gray-900 hx:contrast-more:underline hx:contrast-more:dark:text-gray-50 hx:w-full hx:break-words" href="#solution">Solution
|
||
</a>
|
||
</li></ul>
|
||
<div class="hx:mt-8 hx:border-t hx:bg-white hx:pt-8 hx:shadow-[0_-12px_16px_white] hx:dark:bg-dark hx:dark:shadow-[0_-12px_16px_#111] hx:sticky hx:bottom-0 hx:flex hx:flex-col hx:items-start hx:gap-2 hx:pb-8 hx:border-gray-200 hx:dark:border-neutral-800 hx:contrast-more:border-t hx:contrast-more:border-neutral-400 hx:contrast-more:shadow-none hx:contrast-more:dark:border-neutral-400">
|
||
<button aria-hidden="true" id="backToTop" onClick="scrollUp();" class="hx:cursor-pointer hx:transition-all hx:duration-75 hx:opacity-0 hx:text-xs hx:font-medium hx:text-gray-500 hx:hover:text-gray-900 hx:dark:text-gray-400 hx:dark:hover:text-gray-100 hx:contrast-more:text-gray-800 hx:contrast-more:dark:text-gray-50">
|
||
<span>Scroll to top</span>
|
||
<svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="1.5" stroke="currentColor" class="hx:inline hx:ltr:ml-1 hx:rtl:mr-1 hx:h-3.5 hx:w-3.5 hx:rounded-full hx:border hx:border-gray-500 hx:hover:border-gray-900 hx:dark:border-gray-400 hx:dark:hover:border-gray-100 hx:contrast-more:border-gray-800 hx:contrast-more:dark:border-gray-50">
|
||
<path stroke-linecap="round" stroke-linejoin="round" d="M4.5 15.75l7.5-7.5 7.5 7.5" />
|
||
</svg>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
</nav>
|
||
|
||
|
||
<article class="hx:w-full hx:break-words hx:flex hx:min-h-[calc(100vh-var(--navbar-height))] hx:min-w-0 hx:justify-center hx:pb-8 hx:pr-[calc(env(safe-area-inset-right)-1.5rem)]">
|
||
<main class="hx:w-full hx:min-w-0 hx:max-w-6xl hx:px-6 hx:pt-4 hx:md:px-12">
|
||
|
||
<div class="content">
|
||
<h1>Sum</h1>
|
||
<h1>Task</h1><ol>
|
||
<li>
|
||
<p>You need to create a <code>Sum</code> class which will sum integers from command line arguments and output the sum to console.</p>
|
||
</li>
|
||
<li>
|
||
<p>Examples:</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>java Sum <span style="color:#ae81ff">1</span> <span style="color:#ae81ff">2</span> <span style="color:#ae81ff">3</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>Expected output: <code>6</code>.</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>java Sum <span style="color:#ae81ff">1</span> <span style="color:#ae81ff">2</span> -3</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>Expected output: <code>0</code>.</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>java Sum <span style="color:#e6db74">"1 2 3"</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>Expected output: <code>6</code>.</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>java Sum <span style="color:#e6db74">"1 2"</span> <span style="color:#e6db74">" 3"</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>Expected output: <code>6</code>.</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>java Sum <span style="color:#e6db74">" "</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>Expected output: <code>0</code>.</p>
|
||
</li>
|
||
<li>
|
||
<p>Arguments can be:</p>
|
||
<ul>
|
||
<li>digits,</li>
|
||
<li>signes <code>+</code> and <code>-</code>,</li>
|
||
<li><a href="https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/lang/Character.html#isWhitespace%28char%29"target="_blank" rel="noopener">space symbols</a></li>
|
||
</ul>
|
||
</li>
|
||
<li>
|
||
<p>You can assume that <code>int</code> type is sufficient for in-between calculations and result.</p>
|
||
</li>
|
||
<li>
|
||
<p>Before doing the task make sure to read docs for classes <a href="https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/lang/String.html"target="_blank" rel="noopener"><code>String</code></a> and <a href="https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/lang/Integer.html"target="_blank" rel="noopener"><code>Integer</code></a>.</p>
|
||
</li>
|
||
<li>
|
||
<p>For debugging use <a href="https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/lang/System.html#err"target="_blank" rel="noopener"><code>System.err</code></a>, because it will be ingnored by the testing program.</p>
|
||
</li>
|
||
</ol>
|
||
<hr>
|
||
<h2>Solution<span class="hx:absolute hx:-mt-20" id="solution"></span>
|
||
<a href="#solution" class="subheading-anchor" aria-label="Permalink for this section"></a></h2><p>After reading about <a href="https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/lang/String.html"target="_blank" rel="noopener"><code>String</code></a>, <a href="https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/lang/Integer.html"target="_blank" rel="noopener"><code>Integer</code></a>, <a href="https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/lang/System.html#err"target="_blank" rel="noopener"><code>System.err</code></a> we now know about some usefull methods:</p>
|
||
<ul>
|
||
<li><a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Integer.html#parseInt-java.lang.String-"target="_blank" rel="noopener"><code>Integer.parseInt(String s, int radix)</code></a> which parses the string argument as a signed integer in the radix specified by the second argument. So it basically converts a number from the <code>String</code> data type to <code>int</code>.</li>
|
||
<li><a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Character.html#isWhitespace-char-"target="_blank" rel="noopener"><code>Character.isWhitespace(char ch)</code></a> which checks if a character <code>ch</code> is a space symbol or not.</li>
|
||
</ul>
|
||
<p>Now let’s start coding. Firstly let’s define the structure of our program. I will be putting the name of the file and its path (if it’s nessesary) at the first line comment.</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-java" data-lang="java"><span style="display:flex;"><span><span style="color:#75715e">// Sum.java</span>
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#66d9ef">public</span> <span style="color:#66d9ef">class</span> <span style="color:#a6e22e">Sum</span> {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">public</span> <span style="color:#66d9ef">static</span> <span style="color:#66d9ef">void</span> <span style="color:#a6e22e">main</span>(String<span style="color:#f92672">[]</span> args) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// ...</span>
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>}</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>Okay that’s done. What do we do next? Let’s look at <code>String[] args</code> argument to our <code>main</code> method. It represents an array of command line arguments which we need to sum. So now we made our task a little bit easier. Now we can just say that we need to find sum of elements of array <code>args</code>.</p>
|
||
<p>How are we going to do it though? First let’s understand what we can do with this array. Let’s modify our class a little bit.</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-java" data-lang="java"><span style="display:flex;"><span><span style="color:#75715e">// Sum.java</span>
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#66d9ef">public</span> <span style="color:#66d9ef">class</span> <span style="color:#a6e22e">Sum</span> {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">public</span> <span style="color:#66d9ef">static</span> <span style="color:#66d9ef">void</span> <span style="color:#a6e22e">main</span>(String<span style="color:#f92672">[]</span> args) {
|
||
</span></span><span style="display:flex;"><span> System.<span style="color:#a6e22e">out</span>.<span style="color:#a6e22e">println</span>(args.<span style="color:#a6e22e">length</span>);
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>}</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>We’ve added <code>System.out.println(args.length)</code> which takes the field <code>length</code> from our <code>args</code> object and prints it to the console.</p>
|
||
<p>Let’s try it. First compile our class using</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>$ javac Sum.java</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>And then we can do some manual testing.</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>$ java Sum <span style="color:#ae81ff">1</span> <span style="color:#ae81ff">2</span> <span style="color:#ae81ff">3</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">3</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>We got <code>3</code> as an output as expected. We gave our program 3 command line arguments: <code>1</code>, <code>2</code> and <code>3</code>.</p>
|
||
<p>Here are all of the examples</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>$ java Sum <span style="color:#ae81ff">1</span> <span style="color:#ae81ff">2</span> -3
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">3</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>$ java Sum <span style="color:#e6db74">"1 2 3"</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">1</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hx:overflow-x-auto hx:mt-6 hx:flex hx:flex-col hx:rounded-lg hx:border hx:py-4 hx:px-4 hx:border-gray-200 hx:contrast-more:border-current hx:contrast-more:dark:border-current hx:border-blue-200 hx:bg-blue-100 hx:text-blue-900 hx:dark:border-blue-200/30 hx:dark:bg-blue-900/30 hx:dark:text-blue-200">
|
||
<p class="hx:flex hx:items-center hx:font-medium"><svg height=16px class="hx:inline-block hx:align-middle hx:mr-2" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>Note</p>
|
||
|
||
<div class="hx:w-full hx:min-w-0 hx:leading-7">
|
||
<div class="hx:mt-6 hx:leading-7 hx:first:mt-0"><p>Notice, that we got 1 instead of 3. That’s because we put our arguments in <code>""</code> so this becomes a single string argument.</p></div>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>$ java Sum <span style="color:#e6db74">"1 2"</span> <span style="color:#e6db74">" 3"</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">2</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>$ java Sum <span style="color:#e6db74">" "</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">1</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hx:overflow-x-auto hx:mt-6 hx:flex hx:flex-col hx:rounded-lg hx:border hx:py-4 hx:px-4 hx:border-gray-200 hx:contrast-more:border-current hx:contrast-more:dark:border-current hx:border-blue-200 hx:bg-blue-100 hx:text-blue-900 hx:dark:border-blue-200/30 hx:dark:bg-blue-900/30 hx:dark:text-blue-200">
|
||
<p class="hx:flex hx:items-center hx:font-medium"><svg height=16px class="hx:inline-block hx:align-middle hx:mr-2" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>Note</p>
|
||
|
||
<div class="hx:w-full hx:min-w-0 hx:leading-7">
|
||
<div class="hx:mt-6 hx:leading-7 hx:first:mt-0"><p>Here program gives us 1 instead of 0, because despite not having any numbers in the arguments a single whitespace is still an argument.</p></div>
|
||
</div>
|
||
</div>
|
||
<p>Now let’s try not only to count our arguments but to list them as well. Let’s modify our program a little bit more.</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-java" data-lang="java"><span style="display:flex;"><span><span style="color:#75715e">// Sum.java</span>
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#66d9ef">public</span> <span style="color:#66d9ef">class</span> <span style="color:#a6e22e">Sum</span> {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">public</span> <span style="color:#66d9ef">static</span> <span style="color:#66d9ef">void</span> <span style="color:#a6e22e">main</span>(String<span style="color:#f92672">[]</span> args) {
|
||
</span></span><span style="display:flex;"><span> System.<span style="color:#a6e22e">out</span>.<span style="color:#a6e22e">println</span>(<span style="color:#e6db74">"number of arguments: "</span> <span style="color:#f92672">+</span> args.<span style="color:#a6e22e">length</span>);
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">for</span> (String argument : args) {
|
||
</span></span><span style="display:flex;"><span> System.<span style="color:#a6e22e">out</span>.<span style="color:#a6e22e">println</span>(argument);
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>}</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>Here I used <code>for</code> loop to do printing <em><strong>for</strong></em> every <code>String</code> element in <code>args</code>.</p>
|
||
<p>Let’s try this with our examples. And don’t forget to recompile using <code>javac Sum.java</code>.</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>$ java Sum <span style="color:#ae81ff">1</span> <span style="color:#ae81ff">2</span> <span style="color:#ae81ff">3</span>
|
||
</span></span><span style="display:flex;"><span>number of arguments: <span style="color:#ae81ff">3</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">1</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">2</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">3</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>$ java Sum <span style="color:#ae81ff">1</span> <span style="color:#ae81ff">2</span> -3
|
||
</span></span><span style="display:flex;"><span>number of arguments: <span style="color:#ae81ff">3</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">1</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">2</span>
|
||
</span></span><span style="display:flex;"><span>-3</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>$ java Sum <span style="color:#e6db74">"1 2 3"</span>
|
||
</span></span><span style="display:flex;"><span>number of arguments: <span style="color:#ae81ff">1</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">1</span> <span style="color:#ae81ff">2</span> <span style="color:#ae81ff">3</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hx:overflow-x-auto hx:mt-6 hx:flex hx:flex-col hx:rounded-lg hx:border hx:py-4 hx:px-4 hx:border-gray-200 hx:contrast-more:border-current hx:contrast-more:dark:border-current hx:border-blue-200 hx:bg-blue-100 hx:text-blue-900 hx:dark:border-blue-200/30 hx:dark:bg-blue-900/30 hx:dark:text-blue-200">
|
||
<p class="hx:flex hx:items-center hx:font-medium"><svg height=16px class="hx:inline-block hx:align-middle hx:mr-2" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>Note</p>
|
||
|
||
<div class="hx:w-full hx:min-w-0 hx:leading-7">
|
||
<div class="hx:mt-6 hx:leading-7 hx:first:mt-0"><p>Again, notice only <em><strong>one</strong></em> string argument.</p></div>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>$ java Sum <span style="color:#e6db74">"1 2"</span> <span style="color:#e6db74">" 3"</span>
|
||
</span></span><span style="display:flex;"><span>number of arguments: <span style="color:#ae81ff">2</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">1</span> <span style="color:#ae81ff">2</span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#ae81ff">3</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>$ java Sum <span style="color:#e6db74">" "</span>
|
||
</span></span><span style="display:flex;"><span>number of arguments: <span style="color:#ae81ff">1</span>
|
||
</span></span><span style="display:flex;"><span> </span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>Okay, now that we know how to <em><strong>iterate</strong></em> (or do something for every element), we can calculate the <em>sum</em> of all the numbers in the <code>args</code> array. To do that we need to create a new variable <code>sum</code> of <em>integer</em> type and assign it the <strong>value</strong> of <code>0</code>. Then for every number in <code>args</code> we will add it to <code>sum</code>, and so by the end of array we will have the sum of all numbers stored in variable <code>sum</code>. This is what the code will look like</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-java" data-lang="java"><span style="display:flex;"><span><span style="color:#75715e">// Sum.java</span>
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#66d9ef">public</span> <span style="color:#66d9ef">class</span> <span style="color:#a6e22e">Sum</span> {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">public</span> <span style="color:#66d9ef">static</span> <span style="color:#66d9ef">void</span> <span style="color:#a6e22e">main</span>(String<span style="color:#f92672">[]</span> args) {
|
||
</span></span><span style="display:flex;"><span> System.<span style="color:#a6e22e">out</span>.<span style="color:#a6e22e">println</span>(<span style="color:#e6db74">"number of arguments: "</span> <span style="color:#f92672">+</span> args.<span style="color:#a6e22e">length</span>);
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">int</span> sum <span style="color:#f92672">=</span> 0;
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">for</span> (String argument : args) {
|
||
</span></span><span style="display:flex;"><span> sum <span style="color:#f92672">=</span> sum <span style="color:#f92672">+</span> argument;
|
||
</span></span><span style="display:flex;"><span> System.<span style="color:#a6e22e">out</span>.<span style="color:#a6e22e">println</span>(argument);
|
||
</span></span><span style="display:flex;"><span> System.<span style="color:#a6e22e">out</span>.<span style="color:#a6e22e">println</span>(sum);
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> System.<span style="color:#a6e22e">out</span>.<span style="color:#a6e22e">println</span>(sum);
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>}</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>Seems ok. But let’s test it.</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-sh" data-lang="sh"><span style="display:flex;"><span>$ javac Sum.java
|
||
</span></span><span style="display:flex;"><span>Sum.java:9: error: incompatible types: String cannot be converted to int
|
||
</span></span><span style="display:flex;"><span> sum <span style="color:#f92672">=</span> sum + argument;
|
||
</span></span><span style="display:flex;"><span> ^
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">1</span> error</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>We got a compilation error that says <code>String cannot be converted to int</code>. It means that when we try to add 2 variables <code>sum</code> and <code>argument</code> their types don’t match. The type of <code>sum</code> is integer and string for <code>argument</code>. It seems pretty logical because what do we expect when adding for example <code>1</code> and <code>apple</code>?..</p>
|
||
<div class="hx:overflow-x-auto hx:mt-6 hx:flex hx:flex-col hx:rounded-lg hx:border hx:py-4 hx:px-4 hx:border-gray-200 hx:contrast-more:border-current hx:contrast-more:dark:border-current hx:border-purple-200 hx:bg-purple-100 hx:text-purple-900 hx:dark:border-purple-200/30 hx:dark:bg-purple-900/30 hx:dark:text-purple-200">
|
||
<p class="hx:flex hx:items-center hx:font-medium"><svg height=16px class="hx:inline-block hx:align-middle hx:mr-2" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>Important</p>
|
||
|
||
<div class="hx:w-full hx:min-w-0 hx:leading-7">
|
||
<div class="hx:mt-6 hx:leading-7 hx:first:mt-0"><p>So we need to <em>cast</em> <code>argument</code> to integer data type so that we can add it to <code>sum</code>.</p></div>
|
||
</div>
|
||
</div>
|
||
<p>We can do so using <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Integer.html#parseInt-java.lang.String-"target="_blank" rel="noopener"><code>Integer.parseInt()</code></a> method.</p>
|
||
<p>It takes a <code>String s</code> and returns an <code>int</code>, which a string <code>s</code> represents. For example this code will work as expected</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-java" data-lang="java"><span style="display:flex;"><span><span style="color:#75715e">// ParseIntExample.java</span>
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#66d9ef">public</span> <span style="color:#66d9ef">class</span> <span style="color:#a6e22e">ParseIntExample</span> {
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">public</span> <span style="color:#66d9ef">static</span> <span style="color:#66d9ef">void</span> <span style="color:#a6e22e">main</span>(String<span style="color:#f92672">[]</span> args) {
|
||
</span></span><span style="display:flex;"><span> String s <span style="color:#f92672">=</span> <span style="color:#e6db74">"123"</span>;
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">int</span> sum <span style="color:#f92672">=</span> 321;
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">//! int result = s + sum;</span>
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>}</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>The commented out line (<code>//!</code>) would have given us an exception.</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span>$ javac ParseIntExample.java
|
||
</span></span><span style="display:flex;"><span>ParseIntExample.java:8: error: incompatible types: String cannot be converted to int
|
||
</span></span><span style="display:flex;"><span> int result <span style="color:#f92672">=</span> s + sum;
|
||
</span></span><span style="display:flex;"><span> ^
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">1</span> error</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hx:overflow-x-auto hx:mt-6 hx:flex hx:flex-col hx:rounded-lg hx:border hx:py-4 hx:px-4 hx:border-gray-200 hx:contrast-more:border-current hx:contrast-more:dark:border-current hx:border-purple-200 hx:bg-purple-100 hx:text-purple-900 hx:dark:border-purple-200/30 hx:dark:bg-purple-900/30 hx:dark:text-purple-200">
|
||
<p class="hx:flex hx:items-center hx:font-medium"><svg height=16px class="hx:inline-block hx:align-middle hx:mr-2" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>Important</p>
|
||
|
||
<div class="hx:w-full hx:min-w-0 hx:leading-7">
|
||
<div class="hx:mt-6 hx:leading-7 hx:first:mt-0"><p>Please note that if we change <code>result</code> data type to <code>String</code>, the code will work just fine.</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-java" data-lang="java"><span style="display:flex;"><span><span style="color:#75715e">// ParseIntExample.java</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#66d9ef">public</span> <span style="color:#66d9ef">class</span> <span style="color:#a6e22e">ParseIntExample</span> {
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">public</span> <span style="color:#66d9ef">static</span> <span style="color:#66d9ef">void</span> <span style="color:#a6e22e">main</span>(String<span style="color:#f92672">[]</span> args) {
|
||
</span></span><span style="display:flex;"><span> String s <span style="color:#f92672">=</span> <span style="color:#e6db74">"123"</span>;
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">int</span> sum <span style="color:#f92672">=</span> 321;
|
||
</span></span><span style="display:flex;"><span> String result <span style="color:#f92672">=</span> s <span style="color:#f92672">+</span> sum;
|
||
</span></span><span style="display:flex;"><span> System.<span style="color:#a6e22e">out</span>.<span style="color:#a6e22e">println</span>(result);
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>}</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span>$ javac ParseIntExample.java <span style="color:#f92672">&&</span> java ParseIntExample
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">123321</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>In this case <code>sum</code> will be <em><strong>automatically casted</strong></em> to <code>String</code> and two strings will just concatenate.</p></div>
|
||
</div>
|
||
</div>
|
||
<p>So we figured out that we need to cast <code>argument</code> to integer type. Let’s change our code and test it.</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-java" data-lang="java"><span style="display:flex;"><span><span style="color:#75715e">// Sum.java</span>
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#66d9ef">public</span> <span style="color:#66d9ef">class</span> <span style="color:#a6e22e">Sum</span> {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">public</span> <span style="color:#66d9ef">static</span> <span style="color:#66d9ef">void</span> <span style="color:#a6e22e">main</span>(String<span style="color:#f92672">[]</span> args) {
|
||
</span></span><span style="display:flex;"><span> System.<span style="color:#a6e22e">out</span>.<span style="color:#a6e22e">println</span>(<span style="color:#e6db74">"number of arguments: "</span> <span style="color:#f92672">+</span> args.<span style="color:#a6e22e">length</span>);
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">int</span> sum <span style="color:#f92672">=</span> 0;
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">for</span> (String argument : args) {
|
||
</span></span><span style="display:flex;"><span> sum <span style="color:#f92672">=</span> sum <span style="color:#f92672">+</span> Integer.<span style="color:#a6e22e">parseInt</span>(argument);
|
||
</span></span><span style="display:flex;"><span> System.<span style="color:#a6e22e">out</span>.<span style="color:#a6e22e">println</span>(
|
||
</span></span><span style="display:flex;"><span> <span style="color:#e6db74">"current argument: "</span> <span style="color:#f92672">+</span> argument <span style="color:#f92672">+</span> <span style="color:#e6db74">", current sum: "</span> <span style="color:#f92672">+</span> sum
|
||
</span></span><span style="display:flex;"><span> );
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> System.<span style="color:#a6e22e">out</span>.<span style="color:#a6e22e">println</span>(<span style="color:#e6db74">"final sum: "</span> <span style="color:#f92672">+</span> sum);
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>}</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span>$ java Sum <span style="color:#ae81ff">1</span> <span style="color:#ae81ff">2</span> <span style="color:#ae81ff">3</span>
|
||
</span></span><span style="display:flex;"><span>number of arguments: <span style="color:#ae81ff">3</span>
|
||
</span></span><span style="display:flex;"><span>current argument: 1, current sum: <span style="color:#ae81ff">1</span>
|
||
</span></span><span style="display:flex;"><span>current argument: 2, current sum: <span style="color:#ae81ff">3</span>
|
||
</span></span><span style="display:flex;"><span>current argument: 3, current sum: <span style="color:#ae81ff">6</span>
|
||
</span></span><span style="display:flex;"><span>final sum: <span style="color:#ae81ff">6</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span>$ java Sum <span style="color:#ae81ff">1</span> <span style="color:#ae81ff">2</span> -3
|
||
</span></span><span style="display:flex;"><span>number of arguments: <span style="color:#ae81ff">3</span>
|
||
</span></span><span style="display:flex;"><span>current argument: 1, current sum: <span style="color:#ae81ff">1</span>
|
||
</span></span><span style="display:flex;"><span>current argument: 2, current sum: <span style="color:#ae81ff">3</span>
|
||
</span></span><span style="display:flex;"><span>current argument: -3, current sum: <span style="color:#ae81ff">0</span>
|
||
</span></span><span style="display:flex;"><span>final sum: <span style="color:#ae81ff">0</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span>$ java Sum <span style="color:#e6db74">"1 2 3"</span>
|
||
</span></span><span style="display:flex;"><span>number of arguments: <span style="color:#ae81ff">1</span>
|
||
</span></span><span style="display:flex;"><span>Exception in thread <span style="color:#e6db74">"main"</span> java.lang.NumberFormatException: For input string: <span style="color:#e6db74">"1 2 3"</span>
|
||
</span></span><span style="display:flex;"><span> at java.base/java.lang.NumberFormatException.forInputString<span style="color:#f92672">(</span>NumberFormatException.java:67<span style="color:#f92672">)</span>
|
||
</span></span><span style="display:flex;"><span> at java.base/java.lang.Integer.parseInt<span style="color:#f92672">(</span>Integer.java:662<span style="color:#f92672">)</span>
|
||
</span></span><span style="display:flex;"><span> at java.base/java.lang.Integer.parseInt<span style="color:#f92672">(</span>Integer.java:778<span style="color:#f92672">)</span>
|
||
</span></span><span style="display:flex;"><span> at Sum.main<span style="color:#f92672">(</span>Sum.java:9<span style="color:#f92672">)</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>As we can see because we have only 1 argument (<code>"1 2 3"</code>) we try to parse it as an integer but <code>"1 2 3"</code> contains empty spaces, so it can’t be parsed as an integer.</p>
|
||
<p>We need to manually extract numeric values from the <code>argument</code> string.</p>
|
||
<p>In order to do that we will iterate over each symbol of the <code>argument</code> string and extract numeric values.</p>
|
||
<p>We will have another variable <code>number</code> of <code>String</code> type in which we will be storing extracted numeric values.</p>
|
||
<p>For every character or symbol in the string, we will check it to be an empty space or a digit. If it is a digit, we will add/concatenate with <code>number</code>, and if it is an empty space, we will add the numeric value of <code>number</code> to <code>sum</code> and then assign empty string to <code>number</code> because we reached the end of the current number and are ready to move to the next one.</p>
|
||
<div class="hx:overflow-x-auto hx:mt-6 hx:flex hx:flex-col hx:rounded-lg hx:border hx:py-4 hx:px-4 hx:border-gray-200 hx:contrast-more:border-current hx:contrast-more:dark:border-current hx:border-purple-200 hx:bg-purple-100 hx:text-purple-900 hx:dark:border-purple-200/30 hx:dark:bg-purple-900/30 hx:dark:text-purple-200">
|
||
<p class="hx:flex hx:items-center hx:font-medium"><svg height=16px class="hx:inline-block hx:align-middle hx:mr-2" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>Important</p>
|
||
|
||
<div class="hx:w-full hx:min-w-0 hx:leading-7">
|
||
<div class="hx:mt-6 hx:leading-7 hx:first:mt-0"><p>It is important to add numeric value of <code>number</code> (if it’s not empty) to <code>sum</code> after we iterated over the entire string because if it ends like this <code>"1 2 3"</code>, we don’t nessesarily have an empty space at the end so <code>"3"</code> (in this case) will be stored in <code>number</code> but NOT added to <code>sum</code>.</p></div>
|
||
</div>
|
||
</div>
|
||
<p>Let’s implement those ideas into solution. We will get rid of all the <code>println</code> messages so it’s not drawing our attention.</p>
|
||
<div class="hx:overflow-x-auto hx:mt-6 hx:flex hx:flex-col hx:rounded-lg hx:border hx:py-4 hx:px-4 hx:border-gray-200 hx:contrast-more:border-current hx:contrast-more:dark:border-current hx:border-blue-200 hx:bg-blue-100 hx:text-blue-900 hx:dark:border-blue-200/30 hx:dark:bg-blue-900/30 hx:dark:text-blue-200">
|
||
<p class="hx:flex hx:items-center hx:font-medium"><svg height=16px class="hx:inline-block hx:align-middle hx:mr-2" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>Note</p>
|
||
|
||
<div class="hx:w-full hx:min-w-0 hx:leading-7">
|
||
<div class="hx:mt-6 hx:leading-7 hx:first:mt-0"><p>Also I want to point out that we can’t just iterate over <code>String</code>. First we need to turn it into an <em><strong>array of characters</strong></em> using <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#toCharArray--"target="_blank" rel="noopener"><code>String.toCharArray()</code></a> method.</p></div>
|
||
</div>
|
||
</div>
|
||
<div class="hx:overflow-x-auto hx:mt-6 hx:flex hx:flex-col hx:rounded-lg hx:border hx:py-4 hx:px-4 hx:border-gray-200 hx:contrast-more:border-current hx:contrast-more:dark:border-current hx:border-blue-200 hx:bg-blue-100 hx:text-blue-900 hx:dark:border-blue-200/30 hx:dark:bg-blue-900/30 hx:dark:text-blue-200">
|
||
<p class="hx:flex hx:items-center hx:font-medium"><svg height=16px class="hx:inline-block hx:align-middle hx:mr-2" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>Note</p>
|
||
|
||
<div class="hx:w-full hx:min-w-0 hx:leading-7">
|
||
<div class="hx:mt-6 hx:leading-7 hx:first:mt-0"><p>We will be checking for an empty space using <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Character.html#isWhitespace-char-"target="_blank" rel="noopener"><code>Character.isWhitespace(char ch)</code></a> which outputs <code>true</code> or <code>false</code> accordingly.</p></div>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-java" data-lang="java"><span style="display:flex;"><span><span style="color:#75715e">// Sum.java</span>
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#66d9ef">public</span> <span style="color:#66d9ef">class</span> <span style="color:#a6e22e">Sum</span> {
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">public</span> <span style="color:#66d9ef">static</span> <span style="color:#66d9ef">void</span> <span style="color:#a6e22e">main</span>(String<span style="color:#f92672">[]</span> args) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">int</span> sum <span style="color:#f92672">=</span> 0;
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">for</span> (String argument : args) {
|
||
</span></span><span style="display:flex;"><span> String number <span style="color:#f92672">=</span> <span style="color:#e6db74">""</span>; <span style="color:#75715e">// we will form numbers here</span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">for</span> (<span style="color:#66d9ef">char</span> c : argument.<span style="color:#a6e22e">toCharArray</span>()) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">if</span> (<span style="color:#f92672">!</span>Character.<span style="color:#a6e22e">isWhitespace</span>(c)) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// if character is not whitespace</span>
|
||
</span></span><span style="display:flex;"><span> number <span style="color:#f92672">=</span> number <span style="color:#f92672">+</span> c; <span style="color:#75715e">// concatenate new digit</span>
|
||
</span></span><span style="display:flex;"><span> } <span style="color:#66d9ef">else</span> {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// if character is whitespace</span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">if</span> (<span style="color:#f92672">!</span>number.<span style="color:#a6e22e">isEmpty</span>()) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// if number is not empty</span>
|
||
</span></span><span style="display:flex;"><span> sum <span style="color:#f92672">=</span> sum <span style="color:#f92672">+</span> Integer.<span style="color:#a6e22e">parseInt</span>(number); <span style="color:#75715e">// add number to sum</span>
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span> number <span style="color:#f92672">=</span> <span style="color:#e6db74">""</span>; <span style="color:#75715e">// empty the number</span>
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// check for any remaining digits in number</span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">if</span> (<span style="color:#f92672">!</span>number.<span style="color:#a6e22e">isEmpty</span>()) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// if number is not empty</span>
|
||
</span></span><span style="display:flex;"><span> sum <span style="color:#f92672">=</span> sum <span style="color:#f92672">+</span> Integer.<span style="color:#a6e22e">parseInt</span>(number); <span style="color:#75715e">// add number to sum</span>
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> System.<span style="color:#a6e22e">out</span>.<span style="color:#a6e22e">println</span>(sum);
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>}</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span>$ java Sum <span style="color:#ae81ff">1</span> <span style="color:#ae81ff">2</span> <span style="color:#ae81ff">3</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">6</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span>$ java Sum <span style="color:#ae81ff">1</span> <span style="color:#ae81ff">2</span> -3
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">0</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span>$ java Sum <span style="color:#e6db74">"1 2 3"</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">6</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span>$ java Sum <span style="color:#e6db74">"1 2"</span> <span style="color:#e6db74">" 3"</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">6</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span>$ java Sum <span style="color:#e6db74">" "</span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#ae81ff">0</span></span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>This code works and passes all the tests!</p>
|
||
<p>But can we improve it? One efficiency improvement we can make is to get rid of concatenating strings. You can read why it’s bad <a href="https://stackoverflow.com/questions/18561424/using-for-strings-in-a-loop-is-it-bad-practice"target="_blank" rel="noopener">here</a> or <a href="https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.reddit.com/r/javahelp/comments/19e9jic/question_about_dont_concat_string_in_a_loop/&ved=2ahUKEwiCpva0y-GTAxUeB9sEHbvzHj4QFnoECCAQAQ&usg=AOvVaw3gk39Xk7Jz9_PmKVIO81nK"target="_blank" rel="noopener">here</a>.</p>
|
||
<p>We can use <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/StringBuilder.html"target="_blank" rel="noopener">StringBuilder</a> because it can <em><strong>build</strong></em> strings more efficiently.</p>
|
||
<p>So here’s the updated code</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-java" data-lang="java"><span style="display:flex;"><span><span style="color:#75715e">// Sum.java</span>
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#66d9ef">public</span> <span style="color:#66d9ef">class</span> <span style="color:#a6e22e">Sum</span> {
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">public</span> <span style="color:#66d9ef">static</span> <span style="color:#66d9ef">void</span> <span style="color:#a6e22e">main</span>(String<span style="color:#f92672">[]</span> args) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">int</span> sum <span style="color:#f92672">=</span> 0;
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">for</span> (String argument : args) {
|
||
</span></span><span style="display:flex;"><span> StringBuilder number <span style="color:#f92672">=</span> <span style="color:#66d9ef">new</span> StringBuilder(); <span style="color:#75715e">// we will form numbers here using StringBuilder</span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">for</span> (<span style="color:#66d9ef">char</span> c : argument.<span style="color:#a6e22e">toCharArray</span>()) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">if</span> (<span style="color:#f92672">!</span>Character.<span style="color:#a6e22e">isWhitespace</span>(c)) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// if character is not whitespace</span>
|
||
</span></span><span style="display:flex;"><span> number.<span style="color:#a6e22e">append</span>(c); <span style="color:#75715e">// concatenate new digit</span>
|
||
</span></span><span style="display:flex;"><span> } <span style="color:#66d9ef">else</span> {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// if character is whitespace</span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">if</span> (<span style="color:#f92672">!</span>number.<span style="color:#a6e22e">isEmpty</span>()) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// if number is not empty</span>
|
||
</span></span><span style="display:flex;"><span> sum <span style="color:#f92672">=</span> sum <span style="color:#f92672">+</span> Integer.<span style="color:#a6e22e">parseInt</span>(number.<span style="color:#a6e22e">toString</span>()); <span style="color:#75715e">// add number to sum</span>
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span> number <span style="color:#f92672">=</span> <span style="color:#66d9ef">new</span> StringBuilder(); <span style="color:#75715e">// empty the number by creating new empty StringBuilder</span>
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// check for any remaining digits in number</span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">if</span> (<span style="color:#f92672">!</span>number.<span style="color:#a6e22e">isEmpty</span>()) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// if number is not empty</span>
|
||
</span></span><span style="display:flex;"><span> sum <span style="color:#f92672">=</span> sum <span style="color:#f92672">+</span> Integer.<span style="color:#a6e22e">parseInt</span>(number.<span style="color:#a6e22e">toString</span>()); <span style="color:#75715e">// add number to sum</span>
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> System.<span style="color:#a6e22e">out</span>.<span style="color:#a6e22e">println</span>(sum);
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>}</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="hx:overflow-x-auto hx:mt-6 hx:flex hx:flex-col hx:rounded-lg hx:border hx:py-4 hx:px-4 hx:border-gray-200 hx:contrast-more:border-current hx:contrast-more:dark:border-current hx:border-purple-200 hx:bg-purple-100 hx:text-purple-900 hx:dark:border-purple-200/30 hx:dark:bg-purple-900/30 hx:dark:text-purple-200">
|
||
<p class="hx:flex hx:items-center hx:font-medium"><svg height=16px class="hx:inline-block hx:align-middle hx:mr-2" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>Important</p>
|
||
|
||
<div class="hx:w-full hx:min-w-0 hx:leading-7">
|
||
<div class="hx:mt-6 hx:leading-7 hx:first:mt-0"><p>Note, that we can’t just do <code>Integer.parseInt(number)</code>, because <code>number</code> is an instance of <code>StringBuilder</code>, not just a regular <code>String</code>. In order to get the current state of the string we can use <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/StringBuilder.html#toString--"target="_blank" rel="noopener"><code>StringBuilder.toString()</code></a> method.</p></div>
|
||
</div>
|
||
</div>
|
||
<div class="hx:overflow-x-auto hx:mt-6 hx:flex hx:flex-col hx:rounded-lg hx:border hx:py-4 hx:px-4 hx:border-gray-200 hx:contrast-more:border-current hx:contrast-more:dark:border-current hx:border-blue-200 hx:bg-blue-100 hx:text-blue-900 hx:dark:border-blue-200/30 hx:dark:bg-blue-900/30 hx:dark:text-blue-200">
|
||
<p class="hx:flex hx:items-center hx:font-medium"><svg height=16px class="hx:inline-block hx:align-middle hx:mr-2" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" aria-hidden="true"><path stroke-linecap="round" stroke-linejoin="round" d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>Note</p>
|
||
|
||
<div class="hx:w-full hx:min-w-0 hx:leading-7">
|
||
<div class="hx:mt-6 hx:leading-7 hx:first:mt-0"><p>Also it’s worth mentioning, that we can shorten operations like thse</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-java" data-lang="java"><span style="display:flex;"><span>arg1 <span style="color:#f92672">=</span> arg1 X arg2</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>to</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-java" data-lang="java"><span style="display:flex;"><span>arg1 X<span style="color:#f92672">=</span> arg2</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>where <code>X</code> is some operation like <code>+</code>, <code>-</code>, <code>*</code>, <code>/</code> and so on.</p></div>
|
||
</div>
|
||
</div>
|
||
<p>Let’s make this change to our code</p>
|
||
<div class="hextra-code-block hx:relative hx:mt-6 hx:first:mt-0 hx:group/code">
|
||
|
||
<div><div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-java" data-lang="java"><span style="display:flex;"><span><span style="color:#75715e">// Sum.java</span>
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span><span style="color:#66d9ef">public</span> <span style="color:#66d9ef">class</span> <span style="color:#a6e22e">Sum</span> {
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">public</span> <span style="color:#66d9ef">static</span> <span style="color:#66d9ef">void</span> <span style="color:#a6e22e">main</span>(String<span style="color:#f92672">[]</span> args) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">int</span> sum <span style="color:#f92672">=</span> 0;
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">for</span> (String argument : args) {
|
||
</span></span><span style="display:flex;"><span> StringBuilder number <span style="color:#f92672">=</span> <span style="color:#66d9ef">new</span> StringBuilder(); <span style="color:#75715e">// we will form numbers here using StringBuilder</span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">for</span> (<span style="color:#66d9ef">char</span> c : argument.<span style="color:#a6e22e">toCharArray</span>()) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">if</span> (<span style="color:#f92672">!</span>Character.<span style="color:#a6e22e">isWhitespace</span>(c)) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// if character is not whitespace</span>
|
||
</span></span><span style="display:flex;"><span> number.<span style="color:#a6e22e">append</span>(c); <span style="color:#75715e">// concatenate new digit</span>
|
||
</span></span><span style="display:flex;"><span> } <span style="color:#66d9ef">else</span> {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// if character is whitespace</span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">if</span> (<span style="color:#f92672">!</span>number.<span style="color:#a6e22e">isEmpty</span>()) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// if number is not empty</span>
|
||
</span></span><span style="display:flex;"><span> sum <span style="color:#f92672">+=</span> Integer.<span style="color:#a6e22e">parseInt</span>(number.<span style="color:#a6e22e">toString</span>()); <span style="color:#75715e">// add number to sum</span>
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span> number <span style="color:#f92672">=</span> <span style="color:#66d9ef">new</span> StringBuilder(); <span style="color:#75715e">// empty the number by creating new empty StringBuilder</span>
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// check for any remaining digits in number</span>
|
||
</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">if</span> (<span style="color:#f92672">!</span>number.<span style="color:#a6e22e">isEmpty</span>()) {
|
||
</span></span><span style="display:flex;"><span> <span style="color:#75715e">// if number is not empty</span>
|
||
</span></span><span style="display:flex;"><span> sum <span style="color:#f92672">+=</span> Integer.<span style="color:#a6e22e">parseInt</span>(number.<span style="color:#a6e22e">toString</span>()); <span style="color:#75715e">// add number to sum</span>
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>
|
||
</span></span><span style="display:flex;"><span> System.<span style="color:#a6e22e">out</span>.<span style="color:#a6e22e">println</span>(sum);
|
||
</span></span><span style="display:flex;"><span> }
|
||
</span></span><span style="display:flex;"><span>}</span></span></code></pre></div></div><div class="hextra-code-copy-btn-container hx:opacity-0 hx:transition hx:group-hover/code:opacity-100 hx:flex hx:gap-1 hx:absolute hx:m-[11px] hx:right-0 hx:top-0">
|
||
<button
|
||
class="hextra-code-copy-btn hx:group/copybtn hx:cursor-pointer hx:transition-all hx:active:opacity-50 hx:bg-primary-700/5 hx:border hx:border-black/5 hx:text-gray-600 hx:hover:text-gray-900 hx:rounded-md hx:p-1.5 hx:dark:bg-primary-300/10 hx:dark:border-white/10 hx:dark:text-gray-400 hx:dark:hover:text-gray-50"
|
||
title="Copy code"
|
||
>
|
||
<div class="hextra-copy-icon hx:group-[.copied]/copybtn:hidden hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
<div class="hextra-success-icon hx:hidden hx:group-[.copied]/copybtn:block hx:pointer-events-none hx:h-4 hx:w-4"></div>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<p>This is it! The code is ready.</p>
|
||
|
||
</div>
|
||
<div class="hx:mt-16"></div>
|
||
<div class="hx:mt-16"></div>
|
||
|
||
</main>
|
||
</article>
|
||
</div>
|
||
|
||
|
||
|
||
|
||
<script defer src="/js/main.js" integrity=""></script>
|
||
<script defer src="/js/flexsearch.9f5b5908f93ae86f1ecd4b043b799f580c2d1654e703dd9357d568ac41b2547a.js" integrity="sha256-n1tZCPk66G8ezUsEO3mfWAwtFlTnA92TV9VorEGyVHo=" crossorigin="anonymous"></script>
|
||
<script defer src="/en.search.js" integrity=""></script>
|
||
</body>
|
||
</html>
|