Difference between an interface and abstract class

Question

Write the difference between an interface and abstract class?

Answer 1

Abstract Class:

i. The abstract class can implement methods.
ii. Class can extend only single abstract class.
iii. Abstract classes must have subclasses.
iv. Methods in the abstract class can be abstract as well as concrete.
v. There can be a constructor for the abstract class.
vi. A class extending a abstract class may or may not implement any of its method.
vii. Any class can extend abstract class.
viii. Members of the abstract class can be protected as well as private.

Interface:

i. Interfaces cannot have body of any of its method.
ii. Interface do not have constructor.
iii. The class can implement many interfaces
iv. The interface can only contain public members.
v. The interfaces should have implementations by the classes
vi. Every methods in the interface should be abstract
vii. Every methods of the interface require to be implemented by the class implementing that interface.
viii. Only interface can extend another interface.