Java Program to Demonstrate the Passed by Reference

Here is a Java Program to Demonstrate the Passed by Reference.

class Test {
  int a, b;

  Test(int i, int j) {
    a = i;
    b = j;
  }

  // pass an object
  void meth(Test o) {
    o.a *=  2;
    o.b /= 2;
  }
}

Here is a Main Class to run the Above Class

class CallByRef {
  public static void main(String args[]) {
    Test ob = new Test(15, 20);
    
    System.out.println("ob.a and ob.b before call: " +
                       ob.a + " " + ob.b);

    ob.meth(ob); 

    System.out.println("ob.a and ob.b after call: " +
                       ob.a + " " + ob.b);
  }
}

Output of Above Java Program
ob.a and ob.b before call: 15 20
ob.a and ob.b after call: 30 10