java 可变参数

可变参数?

可变参数允许调用参数数量不同的方法。请看下面例子中的求和方法。此方法可以调用1个int参数，或2个int参数，或多个int参数。

//int(type) followed ... (three dot's) is syntax of a variable argument.
   public int sum(int... numbers) {
       //inside the method a variable argument is similar to an array.
       //number can be treated as if it is declared as int[] numbers;
       int sum = 0;
       for (int number: numbers) {
           sum += number;
       }
       return sum;
   }

   public static void main(String[] args) {
       VariableArgumentExamples example = new VariableArgumentExamples();
       //3 Arguments
       System.out.println(example.sum(1, 4, 5));//10
       //4 Arguments
       System.out.println(example.sum(1, 4, 5, 20));//30
       //0 Arguments
       System.out.println(example.sum());//0
   }