This is a real newbie question, I think, but I can't seem to find the answer.

I am looking at some javascript code and it uses a triple equal operator. Here's a sample of it:

if (b) return b !== !0 && a.getAttribute("classid") === b
What does that === operator do? I find references to = and == (assign and compare respectively) but I cannot find any reference to ===.

Thanks in advance...