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Multiple inheritance and Multiple Interfaces

aakash bhatt
Ranch Hand

Joined: Jan 09, 2003
Posts: 182
Hi all,
When in Java we can multiple interface why not multiple inheritance.
What disadvantages has taken off by removing multiple inheritance and adding
of multiple interfaces.
Greg Charles

Joined: Oct 01, 2001
Posts: 2968

One big problem with mulitple inheritance is what to do when both base classes implement a particular method differently. If the subclass doesn't override this method, what code should be called? This situation often arises when both base classes themselves extend from a common ancestor. In this case, a class hierarchy diagram would show a diamond pattern of classes.
This conflict doesn't exist for interfaces, because they don't provide implementations. It is perfectly acceptable for a class to implement two interfaces that define the same method. However, if the interfaces defined methods with identical signatures, but differing return types, there would still be a conflict.
[ February 20, 2003: Message edited by: Greg Charles ]
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