update

public/courses/prog-intro/homeworks/sum/SumDouble.java

@@ -3,25 +3,25 @@
 public class SumDouble {
 
     public static void main(String[] args) {
-        double sum = 0; // int -> double
+        double sum = 0;
         for (String argument : args) {
             StringBuilder number = new StringBuilder();
             for (char c : argument.toCharArray()) {
                 if (!Character.isWhitespace(c)) {
                     number.append(c);
                 } else {
-                    if (!number.isEmpty()) {
-                        sum += Double.parseDouble(number.toString()); // Integer.parseInt -> Double.parseDouble())
-                    }
+                    sum += parseNumber(number); // method call
                     number = new StringBuilder();
                 }
             }
 
-            if (!number.isEmpty()) {
-                sum += Double.parseDouble(number.toString()); // Integer.parseInt() -> Double.parseDouble()
-            }
+            sum += parseNumber(number); // method call
         }
 
         System.out.println(sum);
     }
+
+    static double parseNumber(StringBuilder number) {
+        return number.isEmpty() ? 0.0 : Double.parseDouble(number.toString());
+    }
 }