What are Virtual Methods?

Question

Why would you declare a method as \"virtual\".

What is the benefit in using virtual?

Answer 1

Even if you don't plan to derive from the class, marking the method virtual may be necessary in order to mock the class. Some mocking frameworks only allow you to mock virtual methods. Note that methods implementing an interface are virtual implicitly.

I use RhinoMocks which has this restriction and have taken to marking my methods virtual by default for just this reason. For me, this is probably the biggest reason to use virtual methods as the cases where inheritance comes into play are much less frequent.