Is it OK for a factory method to return null?

Question

I\'m wondering about best practice here. Is it good practice for a factory method to return null if it can\'t create anything? Here\'s an example:

ICommand comma         


        

Answer 1

I think it's potentially reasonable for a factory method to return null in some situations, but not if it's a method called CreateCommand. If it were GetCommand or FetchCommand, that might be okay... but a Create method should throw an exception on failure, I would suggest.

Whether you really want it to return null in this situation depends on the bigger picture, of course. (Is there a reasonable null object implementation you could return instead, for example?)