Overview

The standardizeLocale method standardizes a BCP-47 locale code to ensure correct formatting and casing. It converts locale codes to their proper canonical format, making them suitable for use with internationalization APIs and ensuring consistency across your application.

Reference

Parameters

Parameters Description

Returns

string - The standardized BCP-47 locale code, or empty string if the input is invalid

Throws

• Error - If no locale is provided and the instance has no targetLocale configured

Behavior

Common format corrections applied:

• en_US → en-US (underscore to hyphen)
• zh_cn → zh-CN (underscore to hyphen, casing)
• EN-gb → en-GB (language lowercase, region uppercase)
• Fr-ca → fr-CA (proper casing throughout)
• ja_jp → ja-JP (underscore and casing)

Examples

const gt = new GT({
  sourceLocale: 'en',
  targetLocale: 'es-ES'
});

// Standardize various locale formats
console.log(gt.standardizeLocale('en_us')); // "en-US"
console.log(gt.standardizeLocale('zh_cn')); // "zh-CN"
console.log(gt.standardizeLocale('EN-gb')); // "en-GB"
console.log(gt.standardizeLocale('fr-ca')); // "fr-CA"

// Already standardized locales pass through unchanged
console.log(gt.standardizeLocale('es-ES')); // "es-ES"
console.log(gt.standardizeLocale('ja-JP')); // "ja-JP"

Notes

• Converts underscores to hyphens and normalizes casing
• Returns empty string for invalid locale codes
• Language codes become lowercase, region codes become uppercase
• Preserves locale extensions and variants when present

Next Steps

• Validate standardized locales with isValidLocale
• Resolve canonical locales with resolveCanonicalLocale
• Get locale properties with getLocaleProperties