Question on C# related to abstract class and interface

What is the difference b/w abstract class and interface and in which scenario each one should be used?

This question is asked many times in many interviews somehow i was able to answer first part but to satisfy interviewers on second is a bit difficult its a tricky one as well i have searched many times on google but i always get concepts related to both the topics.

can anyone please tell me the real scenarios with example where to use both the concepts?

Thanks in advance.

Hi,

Good Explanation for
Avadhesh Tiwari.

Answer of Avadesh :

An Abstract Class can contain implementation of methods, fields, constructors, etc, while an Interface only contains method and property prototypes. An Interface defines what it can do, and an Abstract Class defines what it is.

Points to use them:

If you anticipate creating multiple versions of your component,create an abstract class. Abstract classes provide a simple and easy way to version your components. By updating the base class, all inheriting classes are automatically updated with the change. Interfaces, on the other hand, cannot be changed once created. If a new version of an interface is required, you must create a whole new interface.
If the functionality you are creating will be useful across a wide range of disparate objects, use an interface. Abstract classes should be used primarily for objects that are closely related, whereas interfaces are best suited for providing common functionality to unrelated classes.
If you are designing small, concise bits of functionality, use interfaces. If you are designing large functional units, use an abstract class.
If you want to provide common, implemented functionality among all implementations of your component, use an abstract class. Abstract classes allow you to partially implement your class, whereas interfaces contain no implementation for any members.

Reference :

http://www.c-sharpcorner.com/forums/difference-between-abstract-class-and-interface

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vishal Jadav10y ago
Yah.
Good explanation.
:)
Rajeesh Menoth10y ago
Hi,

Good Explanation for
Avadhesh Tiwari.

Answer of Avadesh :
An Abstract Class can contain implementation of methods, fields, constructors, etc, while an Interface only contains method and property prototypes. An Interface defines what it can do, and an Abstract Class defines what it is.
Points to use them:
If you anticipate creating multiple versions of your component,create an abstract class. Abstract classes provide a simple and easy way to version your components. By updating the base class, all inheriting classes are automatically updated with the change. Interfaces, on the other hand, cannot be changed once created. If a new version of an interface is required, you must create a whole new interface.
If the functionality you are creating will be useful across a wide range of disparate objects, use an interface. Abstract classes should be used primarily for objects that are closely related, whereas interfaces are best suited for providing common functionality to unrelated classes.
If you are designing small, concise bits of functionality, use interfaces. If you are designing large functional units, use an abstract class.
If you want to provide common, implemented functionality among all implementations of your component, use an abstract class. Abstract classes allow you to partially implement your class, whereas interfaces contain no implementation for any members.
Reference :

http://www.c-sharpcorner.com/forums/difference-between-abstract-class-and-interface