What is the difference between abstract class and interface?
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Answer Posted / srikanth reddy
1. Abstract classes may have some executable methods and
methods left unimplemented. Interfaces contain no
implementation code.
2. An class can implement any number of interfaces, but
subclass at most one abstract class.
3. An abstract class can have nonabstract methods. All
methods of an interface are
abstract.
4. An abstract class can have instance variables. An
interface cannot.
5. An abstract class can define constructor. An interface
cannot.
6. An abstract class can have any visibility: public,
protected, private or none
(package). An interface's visibility must be public or none
(package).
7. An abstract class inherits from Object and includes
methods such as clone() and
equals().
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