Calling overideen method in constructor

Question

Hi ,
I want to know why is the overiden method of subclass is called from super class constructor,below is the code
import java.util.*;
class Super{
     // Broken - constructor invokes an overridable method
     public Super(){
          overrideMe();
     public void overrideMe(){
          System.out.println( " in overide me of super class" );
public final class Sub extends Super{
     private final Date date; // Blank final, set by constructor
     Sub(){
          date = new Date();
     // Overriding method invoked by superclass constructor
     @Override
     public void overrideMe(){
          System.out.println( " in overide me of subclass" );
          System.out.println( date );
     public static void main( String[] args ){
          Sub sub = new Sub();
          sub.overrideMe();
}

Answer 1

Vicky wrote:
My question is still unaswered Y is the overideen method of subclass called when subclass object is not created at allAs EJP already told you:
1. This is false.
2. There is only a single object. There are NOT separate Super/Sub objects. Always. Even after all construction has completed.
That object has everything defined in the superclass and everything defined in the subclass. The subclass's constructor has not yet run, but that doesn't matter. Constructors don't create objects. They only initialize newly created objects to valid states. So we have a single object, with all the Super's fields and all the Sub's fields. The Sub's fields still have their default values (0/false/null). That's all. Polymorphism still works like it always does.
and even there is no reference of subclass tooFalse.
There is one object. It IS-A Super and it IS-A Sub. The "this" reference points to it, so when we call foo(), which is equivalent to this.foo(), we are traversing the "this" reference to get to the single Super/Sub object and call Sub's overriding implementation of foo() if it's present, or super's implementation if it's not overridden.
and also i have another question creating a object of a subclass does it also means creating an object of super class and subclass ?Having read the above, you now know the answer to this.