The Locale class

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- PHP Manual
- intl
- The Locale class

# The Locale class

(PHP 5 >= 5.3.0, PHP 7, PHP 8, PECL intl >= 1.0.0)

## Introduction

A "Locale" is an identifier used to get language, culture, or regionally-specific behavior from an API. PHP locales are organized and identified the same way that the CLDR locales used by ICU (and many vendors of Unix-like operating systems, the Mac, Java, and so forth) use. Locales are identified using RFC 4646 language tags (which use hyphen, not underscore) in addition to the more traditional underscore-using identifiers. Unless otherwise noted the functions in this class are tolerant of both formats.

Examples of identifiers include:

- en-US (English, United States)
- zh-Hant-TW (Chinese, Traditional Script, Taiwan)
- fr-CA, fr-FR (French for Canada and France respectively)

The Locale class (and related procedural functions) are used to interact with locale identifiers--to verify that an ID is well-formed, valid, etc. The extensions used by CLDR in UAX #35 (and inherited by ICU) are valid and used wherever they would be in ICU normally.

Locales cannot be instantiated as objects. All of the functions/methods provided are static.

The null or empty string obtains the "root" locale. The "root" locale is equivalent to "en_US_POSIX" in CLDR. Language tags (and thus locale identifiers) are case insensitive. There exists a canonicalization function to make case match the specification.

## Class synopsis

class Locale {
/* Constants */
public const int ACTUAL_LOCALE;
public const int VALID_LOCALE;
public const null DEFAULT_LOCALE = null;
public const string LANG_TAG;
public const string EXTLANG_TAG;
public const string SCRIPT_TAG;
public const string REGION_TAG;
public const string VARIANT_TAG;
public const string GRANDFATHERED_LANG_TAG;
public const string PRIVATE_TAG;
/* Methods */
public static acceptFromHttp(string `$header`): string|false
public static canonicalize(string `$locale`): ?string
public static composeLocale(array `$subtags`): string|false
public static filterMatches(string `$languageTag`, string `$locale`, bool `$canonicalize` = `false`): ?bool
public static getAllVariants(string `$locale`): ?array
public static getDefault(): string
public static getDisplayLanguage(string `$locale`, ?string `$displayLocale` = `null`): string|false
public static getDisplayName(string `$locale`, ?string `$displayLocale` = `null`): string|false
public static getDisplayRegion(string `$locale`, ?string `$displayLocale` = `null`): string|false
public static getDisplayScript(string `$locale`, ?string `$displayLocale` = `null`): string|false
public static getDisplayVariant(string `$locale`, ?string `$displayLocale` = `null`): string|false
public static getKeywords(string `$locale`): array|false|null
public static getPrimaryLanguage(string `$locale`): ?string
public static getRegion(string `$locale`): ?string
public static getScript(string `$locale`): ?string
public static lookup(
array `$languageTag`,
string `$locale`,
bool `$canonicalize` = `false`,
?string `$defaultLocale` = `null`
): ?string
public static parseLocale(string `$locale`): ?array
public static setDefault(string `$locale`): bool
}

## Predefined Constants

`Locale::DEFAULT_LOCALE`
  Used as locale parameter with the methods of the various locale affected classes, such as NumberFormatter. This constant would make the methods to use default locale.

These constants describe the choice of the locale for the getLocale method of different classes.

`Locale::ACTUAL_LOCALE`
  This is locale the data actually comes from.
`Locale::VALID_LOCALE`
  This is the most specific locale supported by ICU.

These constants define how the Locales are parsed or composed. They should be used as keys in the argument array to locale_compose() and are returned from locale_parse() as keys of the returned associative array.

`Locale::LANG_TAG`
  Language subtag
`Locale::EXTLANG_TAG`
  Extended language subtag
`Locale::SCRIPT_TAG`
  Script subtag
`Locale::REGION_TAG`
  Region subtag
`Locale::VARIANT_TAG`
  Variant subtag
`Locale::GRANDFATHERED_LANG_TAG`
  Grandfathered Language subtag
`Locale::PRIVATE_TAG`
  Private subtag

## See Also

- » RFC 4646 - Tags for Identifying Languages
- » RFC 4647 - Matching of Language Tags
- » Unicode CLDR Project:Common Locale Data Repository
- » IANA Language Subtags Registry
- » ICU User Guide - Locale
- » ICU Locale api

## Table of Contents

- Locale::acceptFromHttp — Tries to find out best available locale based on HTTP "Accept-Language" header
- Locale::canonicalize — Canonicalize the locale string
- Locale::composeLocale — Returns a correctly ordered and delimited locale ID
- Locale::filterMatches — Checks if a language tag filter matches with locale
- Locale::getAllVariants — Gets the variants for the input locale
- Locale::getDefault — Gets the default locale value from the INTL global 'default_locale'
- Locale::getDisplayLanguage — Returns an appropriately localized display name for language of the inputlocale
- Locale::getDisplayName — Returns an appropriately localized display name for the input locale
- Locale::getDisplayRegion — Returns an appropriately localized display name for region of the input locale
- Locale::getDisplayScript — Returns an appropriately localized display name for script of the input locale
- Locale::getDisplayVariant — Returns an appropriately localized display name for variants of the input locale
- Locale::getKeywords — Gets the keywords for the input locale
- Locale::getPrimaryLanguage — Gets the primary language for the input locale
- Locale::getRegion — Gets the region for the input locale
- Locale::getScript — Gets the script for the input locale
- Locale::lookup — Searches the language tag list for the best match to the language
- Locale::parseLocale — Returns a key-value array of locale ID subtag elements
- Locale::setDefault — Sets the default runtime locale