JavaScript Random Positive or Negative Number

Question

I need to create a random -1 or 1 to multiply an already existing number by. Issue is my current random function generates a -1, 0, or 1. What is the most efficient way of doing

Answer 1

why dont you try:

(Math.random() - 0.5) * 2

50% chance of having a negative value with the added benefit of still having a random number generated.

Or if really need a -1/1:

Math.ceil((Math.random() - 0.5) * 2) < 1 ? -1 : 1;