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Abstact or to Interface?!

Gabe Newell

Joined: Dec 07, 2004
Posts: 19
Hi guys,

I have been tucking into my Deitel book: "How to program Java" and I have a question to be clarified.

My question is: when to use abstract classes and interface??! The book doesn't really clarify the difference between them. Can anyone help me out?

Many thanks in advance,

- The Atomic Moonfrog
Mike Gershman
Ranch Hand

Joined: Mar 13, 2004
Posts: 1272
Advantage of interface: You can implement any number of interfaces while you can only extend one class.

Advantage of abstract class: You can supply the implementation of some methods but not others. Interfaces cannot supply any method implementations.

There is a lot more here if you search on the terms "abstract" and "interface".

Mike Gershman
SCJP 1.4, SCWCD in process
Joel McNary

Joined: Aug 20, 2001
Posts: 1824

Check out this thread for a Realy Good Explination (TM) for interface and abstract classes. (Of course, this is just my humble opinion )

Piscis Babelis est parvus, flavus, et hiridicus, et est probabiliter insolitissima raritas in toto mundo.
Layne Lund
Ranch Hand

Joined: Dec 06, 2001
Posts: 3061
This question has been asked a lot before, so you can use the Search tool if you would like more information on it.

Keep coding!


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subject: Abstact or to Interface?!
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