What do you use if you want to ensure that all methods and properties are implemented

Question

Hi All, I was giving a test and got one question. QUESTION: What do you use if you want to ensure that all methods and properties are implemented? a)Inheritance. b)Polymorphism. c)Encapsulation d)Interface.

I think its Interface. Am I right or the. ans is diff?

Answer 1

Yep, use an interface. An interface is basically a contract saying "hey, you need to implement these members, or I'm not going to compile."

Answer 2

Actually, these concepts don't even compare to each other.

Answer 3

An interface will ensure that the class has method stubs for all the methods, but they may not be implemented and may throw NotImplementedExceptions.

A better way to ensure that all methods are implemented would be using unit tests where you check that the methods actually do what they should.

Answer 4

An interface or an abstract class will accomplish what you want. In an abstract class, if a method is marked as abstract, then it must be implemented in the derived class. The question really comes down to which one you should use. An interface, or an abstract class.

The quick answer (and I do mean quick and dirty) is that you should use an interface when you are trying to set up contractual behavior between classes. You should use an abstract class when the set of derived class have some shared behavior.