public class Demo1 {
    public static void main(String[] args) {
        int a = 10;
        int b= 20;
        System.out.println(a+"___"+b);//10__20
        change(a,b);
        System.out.println(a + "___" + b);//10__20
        int []arr={1,2,3};
        System.out.println(arr[2]);//3
        changed( arr);
        System.out.println(arr[2]);//100
    }

    private static void changed(int []arr) {
       arr[2]=100;
        System.out.println(arr[2]);//100
    }

    private static void change(int a,int b ) {
        a=20;
        b=30;
        System.out.println(a + "___" + b);//20___30
    }
}