Static Interfaces

[Arun Kumarr]

Why is that the enclosing interface cannot be marked static whereas the enclosed interface can be marked static?

Any comments!!!

[Barry Gaunt]

public class AClass
{
    static interface IA {
        static interface IB {
            static interface IC {
            }
        }
    }
 
}
  

Enclosing interfaces can be static.
Do you mean a top-level interface? If so, what would a static top-level interface mean to you?
[ July 29, 2005: Message edited by: Barry Gaunt ]

[ankur rathi]

I am surprise, interface means something that is abstract and abstract thing can't be static whether it is inner or outer. It was just my thought. But it is not true, am I not thinking in right way??

Thanks.

[Arun Kumarr]

static interface { //Compiler error - But why??

static interface { //No compiler error
void m1();

}

void m2();

}

[Arun Kumarr]

Sorry forgot to add the interface names!!!


static interface outer{ //Compiler error - But why??

static interface inner{ //No compiler error
void m1();

}

void m2();

}

[Ilja Preuss]

Do you know what static *means* for a nested interface?

How would that meaning translate to toplevel interfaces?

[Arun Kumarr]

Marking a class or an interface static at the top level is only to ensure that it can be accessed without an instance.
So having a interface marked as static at the class level would mean nothing as you can never instantiate your interface.

But..

Marking a interface which is inside a class ensures that the interface can be implemented/extended without having the actual instance of the toplevel enclosing class/interface.

Am I correct barry??

[Layne Lund]

Originally posted by Arun Kumarr:
Marking a class or an interface static at the top level is only to ensure that it can be accessed without an instance.
So having a interface marked as static at the class level would mean nothing as you can never instantiate your interface.

But..

Marking a interface which is inside a class ensures that the interface can be implemented/extended without having the actual instance of the toplevel enclosing class/interface.

Am I correct barry??

Neither top-level classes or interfaces can be declared static. What would this mean? Only nested elements can be declared static. Whether its a variable, method, nested class or interface, the meaning is similar: you don't need an instance of the outer class to access the nested element. This means that your later statement is on the mark. A static interface can be implemented or extended without an instance of the outer class or interface.

Layne