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.

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, taken from the Unicode collation specification.

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.

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 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.

let locale = new Intl.Locale("en-Latn-US-u-co-emoji");
console.log(locale.collation); // Prints "emoji"

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.

let locale = new Intl.Locale("en-Latn-US", { collation: "emoji" });
console.log(locale.collation); // Prints "emoji"

• Intl.Locale