interface within class or interface

[JigaR Parekh]

I found following two question which are confusing me.

1) Which of the following are modifiers that can be applied to an interface that is a member of a directly enclosing class?

a. abstract
b. extends
c. final
d. private
e. protected
f. public

Answer: ADEF

2) Which of the following are modifiers that can be applied to an interface that is a member of a directly enclosing interface?

a. abstract
b. implements
c. final
d. private
e. protected
f. public

Answer: AF



Thx

[Jim Yingst]

Well, at least one of the stated answers is incorrect. Where did you find these questions and answers? I advise you to simply ignore the given answers. What do you think the answers should be, and why?
[ July 17, 2005: Message edited by: Jim Yingst ]

[JigaR Parekh]

I think you are right.
Second quetion i feel is correct and answer is also right.
bcoz default behaviour of an interface is abstract and it should be always public

[Georgy Bolyuba]

Jim Yingst,
please spot an error. Both answers looks correct for me.

This code is compiled just fine:

class Test
{
    abstract interface A {};
    //final interface C {};
    private interface D {};
    protected interface E {};
    public interface F {};
}
 
interface ITest
{
    abstract interface A {};
    //final interface C {};
    //private interface D {};
    //protected interface E {};
    public interface F {};
}

[ July 18, 2005: Message edited by: George Bolyuba ]

[rajan singh]

according to me answeres are correct...

1.
since interface is member of class Test. It means we can apply any modifiers which we can apply to member of class. That is why we can provide public ,private and protected modifiers.
abstract is redundant but we can apply it.

2.
in interface we can never have private or protected modifiers.
so modifiers for member of interfaces are
public
final static
abstarct(redundant)
and we can never use final with interface because intefaces are meant to be implemented.

please let me know if i am wrong...

[Roger Chung-Wee]

default behaviour of an interface is abstract and it should be always public

The public modifier is optional. An interface without an access modifier has package level access.

[Jim Yingst]

[rajan]: and we can never use final with interface because intefaces are meant to be implemented.

But what about this:

interface A {}
 
interface B [B]extends[/B] A {}

[Jim Yingst]

[jigar]: default behaviour of an interface is abstract and it should be always public

[Roger]: The public modifier is optional. An interface without an access modifier has package level access.

Ah, we seem to have lost some context here. Jigar was referring to the second question, which has an interface nested within another interface. This nested interface in implicitly public, not package - not because it's an interface, but because it's nesteed within another interface. All members of an interface are implicitly public; this includes nested classes and interfaces.