java interview question

java interview question

what is the usage of abstract class?

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November 20, 2012 at 5:13 PM

An abstract class is a class that is declared by using the abstract keyword. It may or may not have abstract methods. Abstract classes cannot be instantiated, but they can be extended into sub-classes. Abstract classes are used when you do intend to create a concrete class, but want to make sure that there is some common state in all the subclasses or a possible common implementation for some operations.

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