why we need an abstract class????

Question

why should we need to create an abstract class, we all know that abstract class can not be instantiated and so can interface so what is the major reason to used abstract class.

Ayappan Alagesan · Answer

The major reason for using Abstract class is "Adding some non-abstract methods which is optional for implementing in the inherited class" For Example : A project contains 10 class which has CURD operations out of these 5 classes have additional method call preview.This will be added as "NON-Abstract" method in Abstract class,so that we can use where ever it is needed.

Nitin Sontakke · Answer

This is routinely asked question, if you just search this forum, you will find several questions (and obviously their answers!) http://www.c-sharpcorner.com/forums/why-we-use-abstract-class-in-c-sharp http://www.c-sharpcorner.com/forums/when-to-use-abstract-class-and-interface-class http://www.c-sharpcorner.com/forums/why-we-use-abstract-class http://www.c-sharpcorner.com/forums/use-of-abstract-class

Nitin Sontakke · Answer

My favorite explanation to this is a Math class. Mathematics all over the world is same. However you want to consolidate all the mathematical functions under one class, which is abstract. What possibly can you do by instantiating an object of this class?

Vishal Prajapati · Answer

You need abstract class, when you don't want to instantiate the super class, yet you want to implement some of the functionality. Use Abstract class when there is a 'IS-A' relationship between classes. For example, Lion is a Animal, Cat is an Animal. So, Animal can be an abstract class with common implementation like no. of legs, tail etc.