WAP IN JAVA TO SHOW CALL BY REFERENCE

class Number
{
    int x;
}
public class Thirteen {
    public static void main(String args[])
    {
        Number obj=new Number();
        obj.x=3;
        System.out.println("Value of obj.x before calling incr(): "+obj.x);
        increment(obj);
        System.out.println("Value of obj.x before calling incr(): "+obj.x);
    }
    public static void increment(Number num)
    {
        System.out.println("Value of num.x before incr(): "+num.x);
        num.x=num.x+1;
        System.out.println("Value of num.x after incr(): "+num.x);
    }
 
}