Intl.DateTimeFormat.supportedLocalesOf()

Summary

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.

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 locales argument, see the Intl page.
options

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.

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

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"};
alert(Intl.DateTimeFormat.supportedLocalesOf(locales, options).join(", "));
// → "id-u-co-pinyin, de-ID"

Specifications

Specification Status Comment
ECMAScript Internationalization API Specification 1st Edition (ECMA-402) Standard Initial definition.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 24 29 (29) 11 15 Not supported
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
Basic support Not supported 26 Not supported
bug 864843
Not supported Not supported Not supported

See also

Document Tags and Contributors

Contributors to this page: Sheppy, Norbert, fscholz
Last updated by: fscholz,