Math

`Math.sign`

Returns 1, -1, or 0 indicating the sign of a number

Syntax

JavaScript

Math.sign(x)

Parameters

Parameter	Type	Description
x	number	A number

Return Value

1 if positive, -1 if negative, 0 if zero

Examples

Basic Usage

console.log(Math.sign(5)); // 1
console.log(Math.sign(-5)); // -1
console.log(Math.sign(0)); // 0

Practical Example

const values = [-10, 0, 5, -3, 8];
const signs = values.map(Math.sign);
console.log(signs); // [-1, 0, 1, -1, 1]

Advanced Usage

function direction(velocity: number) {
  switch (Math.sign(velocity)) {
    case 1: return 'forward';
    case -1: return 'backward';
    default: return 'stopped';
  }
}

Understanding Math.sign

The Math.sign method in JavaScript returns 1, -1, or 0 indicating the sign of a number. It belongs to the Math object and is one of the most widely used methods for working with math values in modern JavaScript and TypeScript applications.

The method signature is Math.sign(x). It accepts 1 parameter: x. When called, it returns 1 if positive, -1 if negative, 0 if zero. Understanding when and how to use sign() helps you write more expressive, readable code.

Common use cases for Math.sign include data transformation, input validation, API response processing, and building reusable utility functions. It works well alongside related methods like math-abs, math-floor, math-ceil, enabling you to chain operations together for complex data manipulation pipelines.

Browser support for Math.sign is excellent across all modern browsers including Chrome, Firefox, Safari, and Edge. It is also fully supported in Node.js and Deno. For older environments, transpilation with Babel or a polyfill may be needed.