instanceof operator

[shyam kumarK]

public class aa{
public static void main(String argv[]){
aa a = new aa();
bb b=new bb();
System.out.println(b instanceof a);
}
}
class bb extends aa{}

can someone tell me why the following code fails compilation saying class a cannot be found ?

public class aa{
public static void main(String argv[]){
aa a = new aa();
bb b=new bb();
System.out.println(a instanceof b);
}
}
class bb extends aa{}
when this code compiles and prints false why the first one wont compile ?

[Barry Gaunt]

Both do not compile. Perhaps you should reread the description of instanceof, especially the part about the second operand.

[shyam kumarK]

Hi Barry Gaunt for your kind information the second code compiles and runs fine and prints false
Please check it
Thanks,

[Chandra Bhatt]

Perhaps your code is working under following scenario:

class b extends bb{

}
 
public class aa {
 
public static void main(String... args){
aa a = new aa();
bb b = new bb();

System.out.println(a instanceof b);//prints false
}
}
 
class bb extends aa {

}
 

Anyways it is "informatively" funny.


Thanks,

[Barry Gaunt]

Originally posted by shyam kumarK:
Hi Barry Gaunt for your kind information the second code compiles and runs fine and prints false
Please check it
Thanks,

I did.

[Keith Lynn]

I agree with Chandra. You must have a class definition in your CLASSPATH named b which is an extension of bb.

[Barry Gaunt]

Originally posted by Keith Lynn:
I agree with Chandra. You must have a class definition in your CLASSPATH named b which is an extension of bb.

Or any interface b.

[shyam kumarK]

keith linn was absolutely correct
it was my stupidity to check if instanceof works with rhs being a reference variable ?!