Hi,

Here is two classes A and B. A is super class and B is sub class. Here is the code example:

public class A
{
 public int i=40;


 public void print()
 {
  System.out.println("A");
 }
}


public class B extends A
{
 public int i=20;


 public void print()
 {
  System.out.println("B");
 }


 public static void main(String args[])
 {
  A a = new B();
  A a1 = new A();
  System.out.println(a.i);
  System.out.println(a1.i);
  a.print();
  a1.print();
 }
}

With the help of following line:

A a = new B();

You are creating the object of subclass Thanks