What is the purpose of abstract class?

The purpose of an abstract class (often referred to as an ABC) is to provide an appropriate base class from which other classes can inherit . Abstract classes cannot be used to instantiate objects and serves only as an interface. Attempting to instantiate an object of an abstract class causes a compilation error.

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What is concrete in Java?

A concrete class is a class that has an implementation for all of its methods . They cannot have any unimplemented methods. It can also extend an abstract class or implement an interface as long as it implements all their methods. It is a complete class and can be instantiated.16 Oca 2019

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