Intl.Locale() constructor

The Intl.Locale() constructor creates Intl.Locale objects.

Try it

const korean = new Intl.Locale("ko", {
  script: "Kore",
  region: "KR",
  hourCycle: "h23",
  calendar: "gregory",
});

const japanese = new Intl.Locale("ja-Jpan-JP-u-ca-japanese-hc-h12");

console.log(korean.baseName, japanese.baseName);
// Expected output: "ko-Kore-KR" "ja-Jpan-JP"

console.log(korean.hourCycle, japanese.hourCycle);
// Expected output: "h23" "h12"

Syntax

new Intl.Locale(tag)
new Intl.Locale(tag, options)

Note: Intl.Locale() can only be constructed with new. Attempting to call it without new throws a TypeError.

Parameters

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.
variants: The variants. It should be a dash (-) separated list of unique variant tags, where each tag is any syntactically valid string following the unicode_variant_subtag grammar (either 5–8 alphanumerals or a digit followed by 3 alphanumerals), 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.supportedValuesOf().
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.supportedValuesOf().
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.supportedValuesOf().
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.

Examples

undefined

Basic usage

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

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

Using the Locale constructor with an options object

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"

Specifications

ECMAScript® 2027 Internationalization API Specification