Generics

[victor kamat]

import java.io.*;
import java.util.*;
 
public class Base
{
public static void main(String... s)
{
List<A> lis = new ArrayList<A>();
lis.add(new A());
lis.add(new B());
System.out.println(lis.get(1));
}
}
class A           { public String toString() { return "A"; } }
class B extends A { public String toString() { return "B"; } }

The output of the above code is "B".
My understanding of generics is that the object returned by lis.get(1) is cast to A by the JVM.
So why am I not seeing "A" output.

EDIT by mw: Fixed code tags.
[ February 24, 2007: Message edited by: marc weber ]

[marc weber]

Originally posted by victor kamat:
...My understanding of generics is that the object returned by lis.get(1) is cast to A by the JVM.
So why am I not seeing "A" output...

The reference is cast to type A, but the true runtime type of the object remains B. Does that make sense?

[victor kamat]

Thanks

[Benjamin Samuel]

Here, the subclass B is overriding the toString() method defined in the class A. Thus according to the overriding rules, the invocation of toString() method on the B object(with A's reference) will invoke the B's method. If you had removed the toString() method from B then you would have got 'A' as the output.