Is it better to return null or empty collection?

Question

That\'s kind of a general question (but I\'m using C#), what\'s the best way (best practice), do you return null or empty collection for a method that has a collection as a

Answer 1

Think always in favor of your clients (which are using your api):

Returning 'null' very often makes problems with clients not handling null checks correctly, which causes a NullPointerException during runtime. I have seen cases where such a missing null-check forced a priority production issue (a client used foreach(...) on a null value). During testing the problem did not occur, because the data operated on was slightly different.