Difference between declaring variables before or in loop?

Question

I have always wondered if, in general, declaring a throw-away variable before a loop, as opposed to repeatedly inside the loop, makes any (performance) difference? A (q

Answer 1

I suspect a few compilers could optimize both to be the same code, but certainly not all. So I'd say you're better off with the former. The only reason for the latter is if you want to ensure that the declared variable is used only within your loop.