Compute Sign

Computes either a positive or negative 1, indicating the sign of a number passed into the argument. If the number argument is 0, it will return 0.

Examples in JavaScript
console.log(Math.sign(3));
// expected output: 1

console.log(Math.sign(-3));
// expected output: -1

console.log(Math.sign(0));
// expected output: 0

console.log(Math.sign('-3'));
// expected output: -1

Math.sign(3);     //  1
Math.sign(-3);    // -1
Math.sign('-3');  // -1
Math.sign(0);     //  0
Math.sign(-0);    // -0
Math.sign(NaN);   // NaN
Math.sign('foo'); // NaN
Math.sign();      // NaN