Web/JavaScript/Reference/Global objects/Intl/DateTimeFormat/supportedLocalesOf
The Intl.DateTimeFormat.supportedLocalesOf() method returns an array containing those of the provided locales that are supported in date and time formatting without having to fall back to the runtime's default locale.
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Syntax
Intl.DateTimeFormat.supportedLocalesOf(locales[, options])
Parameters
locales- A string with a BCP 47 language tag, or an array of such strings. For the general form of the
localesargument, see the Intl page. 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 date and time formatting 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 date and time formatting 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 date and time formatting, supportedLocalesOf returns the Indonesian and German language tags unchanged, even though pinyin collation is neither relevant to date and time formatting nor 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.
var locales = ['ban', 'id-u-co-pinyin', 'de-ID'];
var options = { localeMatcher: 'lookup' };
console.log(Intl.DateTimeFormat.supportedLocalesOf(locales, options).join(', '));
// → "id-u-co-pinyin, de-ID"
Specifications
| Specification |
| ECMAScript Internationalization API (ECMA-402)The definition of 'Intl.DateTimeFormat.supportedLocalesOf' in that specification. |
Browser compatibility
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Update compatibility data on GitHub
| Desktop | Mobile | Server | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
supportedLocalesOf
|
Chrome
Full support 24 |
Edge
Full support 12 |
Firefox
Full support 29 |
IE
Full support 11 |
Opera
Full support 15 |
Safari
Full support 10 |
WebView Android
Full support 4.4 |
Chrome Android
Full support 25 |
Firefox Android
Full support 56 |
Opera Android
Full support 14 |
Safari iOS
Full support 10 |
Samsung Internet Android
Full support 1.5 |
nodejs Full support 13.0.0 Full support 13.0.0 Partial support 0.12 Notes' Before version 13.0.0, only the locale data for |
Legend
- Full support
- Full support
- See implementation notes.'
- See implementation notes.
See also
Intl.DateTimeFormat.supportedLocalesOf() by Mozilla Contributors is licensed under CC-BY-SA 2.5.