W3cubDocs

/JavaScript

Intl.Collator.supportedLocalesOf()

The Intl.Collator.supportedLocalesOf() method returns an array containing those of the provided locales that are supported in collation without having to fall back to the runtime's default locale.

Try it

Syntax

Intl.Collator.supportedLocalesOf(locales)
Intl.Collator.supportedLocalesOf(locales, options)

Parameters

locales

A string with a BCP 47 language tag, or an array of such strings. For the general form and interpretation of the locales argument, see Locale identification and negotiation.

options Optional

An object that may have the following property:

localeMatcher

The locale matching algorithm to use. Possible values are "lookup" and "best fit"; the default is "best fit". For information about this option, see the Intl page.

Return value

An array of strings representing a subset of the given locale tags that are supported in collation without having to fall back to the runtime's default locale.

Description

Returns an array with a subset of the language tags provided in locales. The language tags returned are those for which the runtime supports a locale in collation that the locale matching algorithm used considers a match, so that it wouldn't have to fall back to the default locale.

Examples

Using supportedLocalesOf()

Assuming a runtime that supports Indonesian and German but not Balinese in collation, supportedLocalesOf returns the Indonesian and German language tags unchanged, even though pinyin collation is not used with Indonesian and a specialized German for Indonesia is unlikely to be supported. Note the specification of the "lookup" algorithm here — a "best fit" matcher might decide that Indonesian is an adequate match for Balinese since most Balinese speakers also understand Indonesian, and therefore return the Balinese language tag as well.

const locales = ['ban', 'id-u-co-pinyin', 'de-ID'];
const options = { localeMatcher: 'lookup' };
console.log(Intl.Collator.supportedLocalesOf(locales, options).join(', '));
// → "id-u-co-pinyin, de-ID"

Specifications

Browser compatibility

Desktop Mobile Server
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet Deno Node.js
supportedLocalesOf
24
12
29
11
15
10
4.4
25
56
14
10
1.5
1.8
13.0.0
0.12.0
Before version 13.0.0, only the locale data for en-US is available by default. To make full ICU (locale) data available before version 13, see Node.js documentation on the --with-intl option and how to provide the data.

See also

© 2005–2022 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Collator/supportedLocalesOf