How to decide between C# static and non-static methods?

Question

[Edit]

My original-question was \"Why to decide between static and non-static? Both do the same...\"

Unfortunately it was edited to a C#-specific question wh

Answer 1

KISS. If you don't have to call a constructor, even better.

Also, a method being static should tell you a little about how the function operates:

• It doesn't operate on variables outside of what's passed to it.
• It doesn't require any memory other than when the method is called (not counting what is returned from the function)

There are some other important things to note:

• Static methods in some instances (Java) are not able to be overridden/subclassed, so they are better suited for cases where the implementation will not need to change.
• Some would argue that static methods are intrinsically difficult to test.

I would also refer to this thread, and a simple google search which frankly provides copious amounts of discussion on this very topic.