Number

`Number.prototype.toFixed`

Formats a number using fixed-point notation with the specified number of decimal places

Syntax

JavaScript

number.toFixed(digits?)

Parameters

Parameter	Type	Description
digits	number	Number of digits after the decimal point (0-100). Defaults to 0

Return Value

A string representing the number in fixed-point notation

Examples

Basic Usage

const num = 3.14159;
console.log(num.toFixed(2)); // '3.14'
console.log(num.toFixed(4)); // '3.1416'

Practical Example

const price = 9.9;
console.log('$' + price.toFixed(2)); // '$9.90'

Advanced Usage

const value = 1.005;
console.log(value.toFixed(2)); // '1.00' (rounding edge case)
console.log(Math.round(value * 100) / 100); // 1.01

Understanding Number.prototype.toFixed

The Number.prototype.toFixed method in JavaScript formats a number using fixed-point notation with the specified number of decimal places. It belongs to the Number object and is one of the most widely used methods for working with number values in modern JavaScript and TypeScript applications.

The method signature is number.toFixed(digits?). It accepts 1 parameter: digits. When called, it returns a string representing the number in fixed-point notation. Understanding when and how to use toFixed() helps you write more expressive, readable code.

Common use cases for Number.prototype.toFixed include data transformation, input validation, API response processing, and building reusable utility functions. It works well alongside related methods like number-toprecision, number-toexponential, number-tostring, enabling you to chain operations together for complex data manipulation pipelines.

Browser support for Number.prototype.toFixed 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.