Intl.Locale.prototype.collation

The Intl.Locale.prototype.collation property is an accessor property that returns the collation type for the Locale, which is used to order strings according to the locale's rules.

Description

Collation is the process of ordering strings of characters. It is used whenever strings must be sorted and placed into a certain order, from search query results to ordering records in a database. While the idea of placing strings in order might seem trivial, the idea of order can vary from region to region and language to language. The collation property helps to make it easier for JavaScript programmers to access the collation type used by a particular locale.

Below is a table with the available collation types, adapted from the Unicode collation specification.

big5han

Pinyin ordering for Latin, big5 charset ordering for CJK characters (for Chinese)

Note: The big5han collation type is deprecated, not available in Chrome or Edge, and on the way to be removed in Firefox (bug 1630920).

compat

A previous version of the ordering, for compatibility (for Arabic)

dict

Dictionary style ordering (for Sinhala)

direct

Binary code point order

Warning: The direct collation type has been deprecated. Do not use.

ducet

The default Unicode collation element table order

Warning: The ducet collation type is not available to the Web. Use the und locale without a collation type specifier instead. und is the collation that is the closest to ducet.

emoji

Recommended ordering for emoji characters (for the und locale)

eor

European ordering rules (for the und locale)

gb2312

Pinyin ordering for Latin, gb2312han charset ordering for CJK characters (for Chinese)

Note: The gb2312 collation type is deprecated, not available in Chrome or Edge, and on the way to be removed in Firefox (bug 1630920).

phonebk

Phonebook style ordering (for German)

phonetic

Phonetic ordering (sorting based on pronunciation; for Lingala)

pinyin

Pinyin ordering for Latin and for CJK characters (for Chinese)

reformed

Reformed ordering (for Swedish)

Note: This is the default ordering for Swedish whose collation naming is unusual as of May 2022. Since this is the default, request sv instead of requesting sv-u-co-reformed.

Special collation type for string search

Warning: Do not use. In Intl.Collator, this collation is activated via the search value for the usage option. Furthermore, there is currently no API for actually using the collator for search.

searchjl

Special collation type for Korean initial consonant search

standard

Default ordering for each language, except Chinese and, as of May 2022, Swedish

Warning: Do not use explicitly. In general, it's unnecessary to specify this explicitly and specifying this for Swedish is problematic in case the naming of the Swedish collations is changed to be consistent with other languages in the future.

stroke

Pinyin ordering for Latin, stroke order for CJK characters (for Chinese)

trad

Traditional style ordering (such as in Spanish)

unihan

Radical-stroke ordering for Han characters (for Chinese, Japanese, and Korean). Pinyin ordering for Latin in the case of Chinese.

Note: The unihan collation type is not available in Chrome or Edge.

zhuyin

Pinyin ordering for Latin, zhuyin order for Bopomofo and CJK characters (for Chinese)

Examples

Like other locale subtags, the collation type can be added to the Intl.Locale object via the locale string, or a configuration object argument to the constructor.

Adding a collation type via the locale string

In the Unicode locale string spec, collation types are locale key "extension subtags". These subtags add additional data about the locale, and are added to locale identifiers by using the -u extension. Thus, the collation type can be added to the initial locale identifier string that is passed into the Intl.Locale() constructor. To add the collation type, first add the -u extension to the string. Next, add the -co extension to indicate that you are adding a collation type. Finally, add the collation to the string.

const locale = new Intl.Locale("zh-Hant-u-co-zhuyin");
console.log(locale.collation); // Prints "zhuyin"

Adding a collation type via the configuration object argument

The Intl.Locale() constructor has an optional configuration object argument, which can contain any of several extension types, including collation types. Set the collation property of the configuration object to your desired collation type, and then pass it into the constructor.

const locale = new Intl.Locale("zh-Hant", { collation: "zhuyin" });
console.log(locale.collation); // Prints "zhuyin"

Specifications

Specification
ECMAScript Internationalization API Specification
# sec-Intl.Locale.prototype.collation

Browser compatibility

BCD tables only load in the browser

See also