Is there a rule of thumb for when to code a static method vs an instance method?

Question

I\'m learning Java (and OOP) and although it might irrelevant for where I\'m at right now, I was wondering if SO could share some common pitfalls or good design practices.

Answer 1

If you keep state ( a value ) of an object and the method is used to access, or modify the state then you should use an instance method.

Even if the method does not alter the state ( an utility function ) I would recommend you to use an instance method. Mostly because this way you can have a subclass that perform a different action.

For the rest you could use an static method.

:)