Intl.NumberFormat.prototype.format()

The Intl.NumberFormat.prototype.format() method formats a number according to the locale and formatting options of this NumberFormat object.

Syntax

numberFormat.format(number)

Parameters

number
A Number or BigInt to format.

Description

The format getter function formats a number into a string according to the locale and formatting options of this NumberFormat object.

Examples

Using format

Use the format getter function for formatting a single currency value, here for Russia:

var options = { style: 'currency', currency: 'RUB' };
var numberFormat = new Intl.NumberFormat('ru-RU', options);
console.log(numberFormat.format(654321.987));
// → "654 321,99 руб."

Using format with map

Use the format getter function for formatting all numbers in an array. Note that the function is bound to the NumberFormat from which it was obtained, so it can be passed directly to Array.prototype.map. This is considered a historical artefact, as part of a convention which is no longer followed for new features, but is preserved to maintain compatibility with existing programs.

var a = [123456.789, 987654.321, 456789.123];
var numberFormat = new Intl.NumberFormat('es-ES');
var formatted = a.map(n => numberFormat.format(n));
console.log(formatted.join('; '));
// → "123.456,789; 987.654,321; 456.789,123"

Specifications

Specification
ECMAScript Internationalization API (ECMA-402)
The definition of 'Intl.NumberFormat.prototype.format' in that specification.

Browser compatibility

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
formatChrome Full support 24Edge Full support 12
Notes
Full support 12
Notes
Notes Before Edge 18, numbers are rounded to 15 decimal digits. For example, new Intl.NumberFormat('en-US').format(1000000000000005) returns "1,000,000,000,000,010".
Firefox Full support 29IE Full support 11
Notes
Full support 11
Notes
Notes In Internet Explorer 11, numbers are rounded to 15 decimal digits. For example, new Intl.NumberFormat('en-US').format(1000000000000005) returns "1,000,000,000,000,010".
Opera Full support 15Safari Full support 10WebView Android Full support 4.4Chrome Android Full support 25Firefox Android Full support 56Opera Android Full support 14Safari iOS Full support 10Samsung Internet Android Full support 1.5nodejs Full support 0.12
Notes
Full support 0.12
Notes
Notes Before version 13.0.0, only the locale data for en-US is available by default. See the NumberFormat() constructor for more details.

Legend

Full support  
Full support
See implementation notes.
See implementation notes.

See also