Copy sign to number
JavaScript, Math · Oct 7, 2020

Returns the absolute value of the first number, but the sign of the second.
- Use
Math.sign()
to check if the two numbers have the same sign. - Return
x
if they do,-x
otherwise.
const copySign = (x, y) => Math.sign(x) === Math.sign(y) ? x : -x;
copySign(2, 3); // 2
copySign(2, -3); // -2
copySign(-2, 3); // 2
copySign(-2, -3); // -2