Check if variable null before assign to null?

Question

Is variable assignment expensive compared to a null check? For example, is it worth checking that foo is not null before assigning it null?

if (foo != null)          


        

Answer 1

I wouldn't worry about it - it's just extra lines of code to maintain. This is the sort of micro-optimization you should never do unless you have lots of documented proof that it's your bottleneck.