Question

In C#, what is the purpose of marking a class static?

If I have a class that has only static methods, I can mark the class static or not. Why would I want to mark the class static? Would I ever NOT want to mark a class static, if all the methods are static, and if I plan to never add a non-static method?

I looked around and saw some similar questions, but none that were just like this.

Answer 1

Marking a class as static is a declarative statement that you only intend for this type to have static and const members. This is enforced by the compiler and prevents you from accidentally adding an instance method to the type.

Other advantages

• Extension methods can only be defined in static classes
• Prevents users from creating an instance of the class
• Prevents use of the type as a generic argument (thanks Eric!)