--- date: 20200923 id: 1accac75-7a5c-4847-977a-f0ae63454820 title: JavaScript Math library --- # ES6 ## .sign(x) ### Returns - -1 if x is a negative number (including -Infinity). - 0 if x is zero4. - +1 if x is a positive number (including Infinity). - NaN if x is NaN or not a number. ``` javascript console.log(Math.sign(-8)) // -a console.log(Math.sign(3)) // 1 console.log(Math.sign(0)) // 0 console.log(Math.sign(NaN)) // NaN console.log(Math.sign(-Infinity)) // -1 console.log(Math.sign(Infinity)) // 1 ``` ## .trunc(x) ``` javascript console.log(Math.trunc(3.1)) // 3 console.log(Math.trunc(3.9)) // 3 console.log(Math.trunc(-3.1)) // 3 console.log(Math.trunc(-3.9)) // 3 ``` ## .cbrt(x) Returns the cube root of x: ``` javascript console.log(Math.cbrt(8)) // 2 console.log(Math.cbrt(27)) // 3 ```