Call by reference example - Java

In this program we have created: 

• a class:  Box9
• a parameterized constructor: Box9(double x, double y, double z)
• a method: volume() where the call by reference is implemented
• a main class: Box9Demo
• an object: b1

import java.util.Scanner;
class Box9{
  double w;
  double d;
  double h;

    Box9(double a, double b,double c){
          w=a;
          d=b;
          h=c;
       }

    void volume(Box9 b1){
            System.out.println("volume ="+b1.w*b1.d*b1.h);
    }
}

class Box9Demo{

public static void main(String args[]){

Box9 b1=new Box9(10.0,12.0,13.0);
 
b1.volume(b1);

 }

}