Which is faster: Math.abs(value) or value * -1 ?

Question

Pretty straightforward, but I just want to know which is faster.

I think simply multiplying a number by -1 is much faster than calling a predefined meth

Answer 1

A style question: Why use a * -1 instead of -a? Apart from that I agree that you should use abs() if you don't know the sign of the number beforehand. I would not care for speed but for readability.