why we use interface in c#?

Question

c#

Ajay Yadav · Answer

An interface is a set of related functions that must be implemented in a derived class. Members of an interface are interface implicitly public and abstract. Interfaces are similar to abstract classes. First both types must be inherited second; you cannot create an instance of either. Although there are several difference as following; · Abstract class can contain some implementation whereas interface doesn't. · Interface can inherit only other interfaces but abstract classes can inherits from other classes and interfaces. · Abstract class can contain constructor and destructors but interface doesn't. · Abstract class contains fields but interface doesn't. So the question is what to choose between these, select interfaces because with the interface, the derived type still can inherit from other type and interfaces are more straightforward then abstract classes.

Yadagiri Reddy · Answer

An interface is not a class . It is an entity that is defined by the word Interface . An interface has no implementation; it only has the signature or in other words, just the definition of the methods without the body. As one of the similarities to Abstract class , it is a contract that is used to define hierarchies for all sub class es or it defines specific set of methods and their arguments. The main difference between them is that a class can implement more than one interface but can only inherit from one abstract class . Since C# doesn't support multiple inheritance, interface s are used to implement multiple inheritance.