preg_match()関数における名前付きサブパターン
?P<任意の名前>
$pattern = '/[a-z]+_(?P<num>\d+)_[a-z]+/'; $string = 'yoshida_43_kazu'; preg_match($pattern, $string, $matches); var_dump($matches['num']); // 43
?P<任意の名前>
$pattern = '/[a-z]+_(?P<num>\d+)_[a-z]+/'; $string = 'yoshida_43_kazu'; preg_match($pattern, $string, $matches); var_dump($matches['num']); // 43