Object Reference

[rex tony]

Good evening to all

public class TestClass {
public static void main(String args[]) {
A o1 = new C();
B o2 = (B) o1;
System.out.println(o1.m1());
System.out.println(o2.i);
}
}
 
class A {
int i = 10;
 
int m1() {
return i;
}
}
 
class B extends A {
int i = 20;
 
int m1() {
return i;
}
}
 
class C extends B {
int i = 30;
 
int m1() {
return i;
}
}

the answer is

It will print 30, 20

how? cause b class instance refer the class c instance.So the the output is 30,30 but i got 30,20.
Any one explain this program
regards
rex
-----
indenting repaired, Bu.

[ September 14, 2007: Message edited by: Burkhard Hassel ]
[ September 14, 2007: Message edited by: Burkhard Hassel ]

[Burkhard Hassel]

Howdy,

you are quite right, b class variable refer the class c instance.

But polymorphy works with methods only, not with fields.

Therefore the b class "20".

The difference is very important.

Yours,
Bu.