Question { HCL, 47428 }

What is the difference between Abstract and Interface?

Answer

my name is skpotla.
the following answer is the exact one.

1.An abstract class is a class with zero or more abstract
methods.
2.Abstract class contains instance variables, concrete
methods in addition to abstract methods.
3.Both abstract class and abstract methods should be
declared as abstract.
4.We can not create and object to the abstract class.
5.We can create a reference to the abstract class type.
6.If you extends the abstract class in a sub class you have
to implement all the methods of the abstract class.
7.If u miss any abstract methods in the sub class then the
sub class should be declared as an abstract class.
8. A class can not be both abstract and final.

1.Interface is a specification of a method prototype.
2.Interface methods are by default abstract and public.
3.Interface contains variables which are by default
public,static and final.
4.Interface contains zero or more abstract methods.
5.We can not create an object to an interface.
6.We can create a reference to the interface type.
7.If we implement an interface we have to implement all its
methods in our sub class.
8. If any one miss then the class should be declared as an
abstract class.
9.Interface can not implements an other interface.
10.Interface can extends the other interface.
11.It is possible to write a class with in an interface.