I (U+0049 LATIN CAPITAL LETTER I), * i (U+0069 LATIN SMALL LETTER I) -> İ (U+0130 LATIN CAPITAL LETTER I WITH DOT ABOVE). * * Unicode CaseFolding.txt defines this case as type 'T', a special case for Turkic languages: * tr and az. PHP 7.3 parser ignores this special cases. so we have to override the * ucfirst and lcfirst methods. * * See https://en.wikipedia.org/wiki/Dotted_and_dotless_I and T30040 * @ingroup Language */ class LanguageTr extends Language { private $uc = [ 'I', 'İ' ]; private $lc = [ 'ı', 'i' ]; /** * @param string $string * @return string */ public function ucfirst( $string ) { $first = mb_substr( $string, 0, 1 ); if ( in_array( $first, $this->lc ) ) { $first = str_replace( $this->lc, $this->uc, $first ); return $first . mb_substr( $string, 1 ); } return parent::ucfirst( $string ); } /** * @param string $string * @return mixed|string */ function lcfirst( $string ) { $first = mb_substr( $string, 0, 1 ); if ( in_array( $first, $this->uc ) ) { $first = str_replace( $this->uc, $this->lc, $first ); return $first . mb_substr( $string, 1 ); } return parent::lcfirst( $string ); } }