interface implements interface?

[jaspreet atwal]

I think I am overlooking a very basic concept here... Why can't we have an Interface that implements an Interface? Or is it that Interfaces should always be top level, there cannot be an Interface somewhere in between a hierarchy tree?

interface ParentInterface{
        void myMethod();
}
 
interface SubInterface implements ParentInterface{
        void anotherMethod();
        void myMethod();
}
 

[Deepa Neela]

interface extends another interface but not implements it, because interface will not contain the implementation (you cannot provide implementation in the interface). So you can just extend it but not implement it.

[Garrett Rowe]

Implements denotes defining an implementation for the methods of an interface. However interfaces have no implementation so that's not possible. An interface can however extend another interface, which means it can add more methods and inherit its type.

interface ParentInterface{
        void myMethod();
}
 
interface SubInterface extends ParentInterface{
        void anotherMethod();
}

[jaspreet atwal]

Garret and Deepa,
Thank you!! That answers my question.

[Ben Souther]

"Deepa",
Please check your private messages regarding an important administrative matter.
-Ben
[ May 06, 2008: Message edited by: Ben Souther ]

[Mayu Mayooresan]

This is my understanding.....

When you implement an Interface to a class you must re-declare all the class and fill them up. Which is not possible in Interface as Interfaces are abstract. So You can't implement an interface to another interface but you can happily extend.

Correct me if my perception is wrong.

Thanks.