how to turn a number negative in javascript

Math.abs("the negative number")

Math.abs(num) => Always positive
-Math.abs(num) => Always negative

-Math.abs(num); // "-" before Math.abs()

const positive = 5;
const negative = -5;
const zero = 0;

Math.sign(positive); // 1
Math.sign(negative); // -1
Math.sign(zero); // 0

Math.sign() has 5 possible return values:
1 // positive number
-1 // negative number
0 // positive zero
-0 // negative zero
NaN // not a number