Intl.Locale() constructor

tag

The Unicode locale identifier string. For the syntax of locale identifier strings, see the Intl main page. Note that the Intl.Locale constructor, unlike most other Intl constructors, does not accept an array of locales or undefined.

options

An object that contains configuration for the Locale. Option values here take priority over extension keys in the locale identifier. Possible properties are:

language

The language. Any syntactically valid string following the unicode_language_subtag grammar (2–3 or 5–8 letters) is accepted, but the implementation only recognizes certain kinds.

script

The script. Any syntactically valid string following the unicode_script_subtag grammar (4 letters) is accepted, but the implementation only recognizes certain kinds.

region

The region. Any syntactically valid string following the unicode_region_subtag grammar (either 2 letters or 3 digits) is accepted, but the implementation only recognizes certain kinds.

calendar

The calendar. Any syntactically valid string following the type grammar (one or more segments of 3–8 alphanumerals, joined by hyphens) is accepted, but the implementation only recognizes certain kinds, which are listed in Intl.Locale.prototype.getCalendars.

collation

The collation. Any syntactically valid string following the type grammar is accepted, but the implementation only recognizes certain kinds, which are listed in Intl.Locale.prototype.getCollations.

numberingSystem

The numbering system. Any syntactically valid string following the type grammar is accepted, but the implementation only recognizes certain kinds, which are listed in Intl.Locale.prototype.getNumberingSystems.

caseFirst

The case-first sort option. Possible values are "upper", "lower", or "false".

hourCycle

The hour cycle. Possible values are "h23", "h12", "h11", or the practically unused "h24", which are explained in Intl.Locale.prototype.getHourCycles

numeric

The numeric sort option. A boolean.

At its very simplest, the Intl.Locale() constructor takes a locale identifier string as its argument:

const us = new Intl.Locale("en-US");

The constructor also takes an optional configuration object argument, which can contain any of several extension types. For example, set the hourCycle property of the configuration object to your desired hour cycle type, and then pass it into the constructor:

const locale = new Intl.Locale("en-US", { hourCycle: "h12" });
console.log(locale.hourCycle); // "h12"

• Polyfill of Intl.Locale in FormatJS
• Intl.Collator
• Canonical Unicode Locale Identifiers in the Unicode locale data markup language spec