参数的传递

    public static void main(String[] args) {
        int a = 2;
        int b = 4;
        change(2, 4);
        System.out.println(a);//猜猜输出a的值是多少？
        System.out.println(b);//猜猜输出b的值是多少？
    }

    public static void change(int a, int b) {
        a = a + b;
        b = a + b;
    }

 public static void main(String[] args) {
        int a = 2;
        int b = 4;
        change(2, 4);
        System.out.println(a);
        System.out.println(b);
    }

    public static void change(int x, int y) {
        x = x + y;
        y = x + y;
    }