Where to check if an object is null or not?

Question

Where do you check if an object that you are passing to a method is null or not?

Should an object need to be tested before calling a method? or within the method tha

Answer 1

I normally let my null checks be controlled by my expectations; if I expect something to be null or am unsure of it, I add a check. Otherwise I don't. Nulllpointer exceptions are among the easiest problems to track, so excessive sprinkling of checks bloats code. In the specific example I'd check nothing, because it's intutitive it's not null.