public static function languagesLocaleCodes()
    {
        static $list;

        if ($list === null) {
            $list = [];
            foreach (static::codes() as $localeCode) {
                if ($languageCode = static::languageCode($localeCode)) {
                    $list[$languageCode][] = $localeCode;
                }
            }
        }

        return $list;
    }
public static function languagesLocaleCodes()
    {
        static $list;

        if ($list === null) {
            $list = [];
            foreach (static::codes() as $localeCode) {
                if ($languageCode = static::languageCode($localeCode)) {
                    $list[$languageCode][] = $localeCode;
                }
            }
        }

        return $list;
    }
public static function languagesLocaleCodes ( ) { static $ list ; if ( $ list === null ) { $ list = [ ] ; foreach ( static :: codes ( ) as $ localeCode ) { if ( $ languageCode = static :: languageCode ( $ localeCode ) ) { $ list [ $ languageCode ] [ ] = $ localeCode ; } } } return $ list ; }
Returns list of locale codes grouped by ISO 639-1, ISO 639-2 or ISO 639-3 language codes
@return array
Returns list of locale codes grouped by ISO 639 - 1 ISO 639 - 2 or ISO 639 - 3 language codes