//int(type) followed ... (three dot's) is syntax of a variable argument.    public static 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) {        // 3 Arguments        System.out.println(sum(1, 4, 5)); // 10        // 4 Arguments        System.out.println(sum(1, 4, 5, 20));//30        // 0 Arguments        System.out.println(sum()); // 0    }