Inheritance Doubt

[Milan Sutaria]

<blockquote><font size="1" face="Verdana, Arial">code:</font><hr><pre name="code" class="core"><font size="2">class X
{
void print (X x){System.out.print("X");}
}

class Y extends X
{
void print (Y y){System.out.print("Y");}
}

class Z extends Y
{
void print (Z z){System.out.print("Z");}
}

class B{
public static void main(String[] args) {

X x2 = new Y();
x2.print(new Y());

X x3 = new Z();
x3.print(new Z());

}
}</font></pre><hr></blockquote>

The above code prints "XX". I expected it to print "YZ"
What i have understood from K&B is
> at compile time x2.print will chk if print method is present(and accessible) in class X. If not present it will give compile time error.
> At runtime polymorphism takes place and the method in class Y is invoked.
Can someone tell me if i have understood it right? If yes, then how does the above code print XX?
I faced the problem while solving Whizlabs6 .. code modified by me.
[ July 17, 2008: Message edited by: Milan Sutaria ]

[Roopa Maheshkumar]

Milan,

The print method is over loaded,not over ridden.

Run time polymorphism takes places for over ridden methods. Overloaded methods are determined at compile time and are based on the reference type.

So x2.print(new Y()); or x3.print(new Z()); is executed, it calls the X print method.

Hope this clarifies.

Thanks,
Roopa

[Milan Sutaria]

Yes, i missed on the point runtime polymorphism is for overridden methods.
Thanks for the reply.