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

From the perspective of managing complexity, a primary software engineering objective, we want to avoid propagating unnecessary cyclomatic complexity to the clients of an API. Returning a null to the client is like returning them the cyclomatic complexity cost of another code branch.

(This corresponds to a unit testing burden. You would need to write a test for the null return case, in addition to the empty collection return case.)