Intl.Locale.prototype.numberingSystem

The Intl.Locale.prototype.numberingSystem property is an accessor property that returns the numeral system used by the locale.

A numeral system is a system for expressing numbers. The numberingSystem property helps to represent the different numeral systems used by various countries, regions, and cultures around the world. As with most internationalization schemas, the numeral systems that can be represented in a Locale object by numberingSystem are standardized by Unicode. A table of the standard Unicode numeral systems can be seen below.

In the Unicode locale string spec, the values that numberingSystem represents correspond to the key nu. nu is considered a locale string "extension subtag". These subtags add additional data about the locale, and are added to locale identifiers by first adding the -u key. To set the numberingSystem value via the string argument to the Locale constructor, first add the -u extension key. Next, add the -nu extension key to indicate that you are adding a value for numberingSystem. Finally, add the numberingSystem value to the string.

let locale = new Intl.Locale("fr-Latn-FR-u-nu-mong");
console.log(locale.numberingSystem); // Prints "mong"

The Intl.Locale constructor has an optional configuration object argument, which can be used to pass extension types. Set the numberingSystem property of the configuration object to your desired numberingSystem value and pass it into the constructor.

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

• Intl.Locale
• Details on the standard Unicode numeral systems