Abstract Class
Quote:
1: It can have implemented Methods
2: A class can inherit only one abstract class
3: We go for Abstract classes on such situations where we need
to give common functionality for group of related classes
4: If we add a new method, then we can provide a default
implementation and so no need to make any change to existing work
5: Static and Instance constants are possible
Interface
Quote:
1: It cannot have implemented Methods.
2: A Class can implement any number of Interfaces
3: We go for Interface on such situations where we need to give
common functionality for group of un-related classes
4: If we add a new method, then we need to change all the existing work
5: Only Static constants are possible