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Is there something called 'inner interface'?

Aakash Goel
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Joined: May 26, 2008
Posts: 198
Inner classes exist. Why not inner interfaces?


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Ankit Garg
Sheriff

Joined: Aug 03, 2008
Posts: 9307
    
  17

Did you try to create an interface within interface or class??


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Aakash Goel
Ranch Hand

Joined: May 26, 2008
Posts: 198
Ankit Garg wrote:Did you try to create an interface within interface or class??


yeah, they do get created.

also, Set is an interface and so is Collection.

But nowhere in K&B is a mention of innner interfaces.

So, I thought probably they are not inner interfaces after all.
Ankit Garg
Sheriff

Joined: Aug 03, 2008
Posts: 9307
    
  17

there are inner interfaces but maybe nothing is asked about them in SCJP that's why nothing about them is given in K&B ...
Vishwanath Krishnamurthi
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Joined: Jun 04, 2007
Posts: 331
Aakash Goel wrote:


So, I thought probably they are not inner interfaces after all.


They are not. Set is an interface that extends from Collection interface and its just a sub-interface... Its not an interface within another interface. From the specs here I see that Sun calls an interface within another interface as a "nested interface" I guess this nesting of an interface in another has only to do with some namespace resolution...


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Paul Clapham
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Joined: Oct 14, 2005
Posts: 18708
    
    8

Vishwanath brings up an important point. There is a rather complicated difference between a "nested class" and an "inner class"... I'm not going to try to explain it because I don't remember it correctly, but you might want to review that. Then it's quite likely that "inner interface" and "nested interface" would be the same concepts.
avi sinha
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Joined: Mar 15, 2009
Posts: 453




you can find questions related to inner ineterfaces too in Dan Chilosam's book.

avi sinha


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Vlado Zajac
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Joined: Aug 03, 2004
Posts: 245
The difference between "inner" and "nested" is that only non-static nested class is called "inner class" (static nested class is not an inner class).

Nested interfaces are always implicitly static so inner interfaces does not exist.
 
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subject: Is there something called 'inner interface'?