when to use abstract class and when to use interface?

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Question Posted / raghu

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when to use abstract class and when to use interface?..

Answer / surendra

Always prefer to interface until you are not sure the behavior
of operations.

chose the abstract class if you are sure for some common behaviors need to share of all objects.

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when to use abstract class and when to use interface?..

Answer / arvind

If you have to implement all of the fuctionalities provided
by, then in this case you should use interfaces because
they force you to implement all of the methods.

on the other hand if you think you have to imlement few of
them , then better you use abstract class.

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when to use abstract class and when to use interface?..

Answer / rod

the bowlingball example I put is when you combine the
abstract class ball with the interface bowlable .. a poor
example perhaps.. lets replace that with

a sock may implement a washable interface which can also be
implemented by cars, shirts, dishes... etc.. so why bother
with this. The reason is for future use as the system grows.
It is more likely that you will run into an object that
needs to be 'washed' then you can in fact call this method
without knowing the lower level details.

its more than just organising things that do or are acted
upon by the same conceptual action. It means that later you
can just use the method because the interface populates the
list of things you can choose from at code completion in the
editor ..for example.

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when to use abstract class and when to use interface?..

Answer / jc

If you want give different implementation(behaviour) to
methods which are available in the interface go for
interface.
If you want give different implementation to particular
methods(that is only some methods which are not similar to
subclass)go for abstract class.

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when to use abstract class and when to use interface?..

Answer / ram

Abstract class is used when and what methods are used
exactly while in interface,the methods are defined for
future use.

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12 No

when to use abstract class and when to use interface?..

Answer / rod

Ram, your last post does not make sense, can you please post
again and say it differently.

The interface methods will naturally depend on the program
you are writing. read the links I referred to ...they are
well written and clear.

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