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Message:

Abstraction

Posted by Matt Gerrans on December 10, 2001 at 5:27 PM

> > Why might we wish to define an abstract class?
>
> Hi..
> An abstract class is defined so as to give a generalised form which can be shared by its subclasses. Sometimes a situation may occur where in one need to define a superclass which can declare a structure for its subclasses but cannot create the meaningful implementation for a method.
> So the subclass according to its necessity extend this abstract class and use the methods decalred with its own customized implementation of the method.

Usually you are better off using interfaces; abstract classes are used in the case where you want to provide some default implementation as well.

- mfg