Explanation for the statements

[Sathya Shanmugam]

Hi friends

Pls give some detail explanation with example for the following statements from KB book


" A Single object can be referred to by reference variable of many different types - as long as they are the same type or a super type of the object"

[Keith Lynn]

Consider this example.

public class Test {
 
   public static void main(String[] args) {
      D d = new D();
      A a = d;
      B b = d;
      C c = d;
 
      System.out.println(a);
      System.out.println(b);
      System.out.println(c);
      System.out.println(d);
   }
 
}
 
class A {
}
 
class B extends A {
}
 
class C extends B {
}
 
class D extends C {
}

There is only one D object created, but it can be referred to as an A, a B, a C, or a D.

[Sathya Shanmugam]

thanks Keith, now I understood the statement clearly with your example.