I'm sold on "don't pass null" for collections. Return empty collections instead of null, this saves you from a world of pain, and it reduces the code size. The

I'm sold on "don't pass null" for collections. Return empty collections instead of null, this saves you from a world of pain, and it reduces the code size. The right way to work around null for scalar variables is to use Maybe/Option, preferably in a language with pattern matching, as opposed to using "magic values" like 0 or the empty string. This means removing null pointer errors by construction.