abstractin

1Sometimes we may come across a situation
2where we cannot provide implementation to
3all the methods in a class. We want to leave the 
4implementation to a class that extends it.
5  In that case we declare a class
6as abstract by using abstract keyword on method
7signature.In my framework I have created my
8PageBase class as super
9class of the all page classes. 
10I have collected all common elements
11and functions into PageBase class and
12all other page classes extent PageBase class.
13By doing so, I don't have to locate very
14common WebElements and it provides
15reusability in my framework.
16Also
171)Abstract classes cannot be instantiated
182)An abstarct classes contains abstract method,
19concrete methods or both.
203)Any class which extends abstarct class must
21  override all methods of abstract class
224)An abstarct class can contain either
23  0 or more abstract method.