GT ClassMethodsLocales
isSupersetLocale
API reference for the GT isSupersetLocale method
Overview
The isSupersetLocale method checks whether one locale is a superset of another within the BCP‑47 hierarchy.
A superset locale is more general and can serve as a fallback for more specific locales.
Reference
Parameters
Prop
Type
Returns
boolean — true if superLocale is a superset of subLocale
Examples
const gt = new GT();
// Base language is superset of regional variant
console.log(gt.isSupersetLocale('en', 'en-US')); // true
console.log(gt.isSupersetLocale('es', 'es-ES')); // true
console.log(gt.isSupersetLocale('zh', 'zh-CN')); // true
// Regional variant is NOT superset of base language
console.log(gt.isSupersetLocale('en-US', 'en')); // false
console.log(gt.isSupersetLocale('es-ES', 'es')); // false
// Same locales
console.log(gt.isSupersetLocale('en-US', 'en-US')); // true
// Different languages
console.log(gt.isSupersetLocale('en', 'es-ES')); // falseNotes
- Uses the BCP‑47 locale hierarchy for comparison
- A locale is always a superset of itself
- Base languages are supersets of their regional variants
- Returns false for completely different languages
Next steps
- Compare the same languages with
isSameLanguage - Compare dialects with
isSameDialect
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