Intl.getCanonicalLocales()

The Intl.getCanonicalLocales() method returns an array containing the canonical locale names. Duplicates will be omitted and elements will be validated as structurally valid language tags.

Intl.getCanonicalLocales(locales)

locales

A list of String values for which to get the canonical locale names.

An array containing the canonical locale names.

Intl.getCanonicalLocales('EN-US'); // ["en-US"]
Intl.getCanonicalLocales(['EN-US', 'Fr']); // ["en-US", "fr"]

Intl.getCanonicalLocales('EN_US');
// RangeError:'EN_US' is not a structurally valid language tag

formatjs Intl.getCanonicalLocales polyfill

• Intl.NumberFormat.supportedLocalesOf()
• Intl.DateTimeFormat.supportedLocalesOf()
• Intl.Collator.supportedLocalesOf()