Difference between Abstract class and Interface

Abstract class is the class in which there is atleast one

abstract method.abstract method is the method which does not

have any body defined in that class.We cannot make any object of

the abstract class.So, that abstract class must be derived by

the subclass which defines all the abstract methods of the super

class.If the sub class doesnot define any abstract meth. of the

super class, then that sub class automatically becomes the

abstract class.When the sub class defines all the abs. meth.s of

the super class then we can make the object of the sub class and

access the other methods of the abs. super class.

An interface is the class that have all the methods as abs.

methods.All the instance variables of an interface must be

declared as final and static.Now we can implement this interface

in another class which must define all the methods of the

interface.Now make the obj. of the class that implemented the

interface.

Interfaces are used where we want the users to use the specified

methods only.Abstract classes are used in inheritence where

there is no need for the class to define any method which must

be defined in the sub classes.

Please the feedback for the above answer.There's too much about

the abstract class n interface so i could not write everything.I

think this must clear ur doubts.