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Optional methods in Interface

 
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Hi all,

I was reading JCF(Java Collections Framework) i found certain methods are Optional in the Collection interface.

Why these optional methods are required in interface ? since interface when implemented all its methods must provide proper implementation

Please help me i am getting confused


 
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jinesh parikh wrote:
Why these optional methods are required in interface ? since interface when implemented all its methods must provide proper implementation



In this case, "optional" is a design feature. It doesn't mean that the implementation is optional, as Java requires that concrete classes implement the methods of its interfaces. It just means that the implementation throws UnsupportedOperationException as its implementation.

Henry
 
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Thanks henry for your answer

 
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