PHP：preg_replace＃符号

foreach ( $words->Reserved as $reserved )
    $code = preg_replace( ( \'/\\b(\' . $reserved . \')\\b/\' ), ( \'<cs_reserved>\' . $reserved . \'</cs_reserved>\' ), $code );

$reserved

#

preg_quote

$code = preg_replace( ( \'/\\b(\' . preg_quote($reserved) . \')\\b/\' ), ( \'<cs_reserved>\' . $reserved . \'</cs_reserved>\' ), $code );