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

I suppose it depends on the implementation, but Math.abs could be as simple as:

function abs(x) {
    return x < 0 ? x * -1 : x;
}

So, in theory, it just adds a quick test before multiplying.

But, yes, negating a negative sign is the sole purpose. The point is that a simple x * -1 is also counter-productive for positive values.

---

@olliej [comments]

True. Simple edit, though. ;)

function abs(x) {
    return Number(x < 0 ? x * -1 : x);
}