Where to check for null, in calling method or in function? [duplicate]

Question

Should a check for null occur before making the call to a function or within the function itself?

Answer 1

I would say within the call itself. That way, you only check for null in one place, not 5 places if you call that function from 5 different spots.

But this isn't a for sure answer. It really depends on the function and what the consequences are of calling it with a null argument.