note 71406 deleted from function.preg-match-all by colder

Note Submitter: Vladimir Kornea ---- Note that preg_match_all() doesn't know how to handle named groups that have the same name even if they are defined in a way that prevents name conflicts: $pattern = '!(?:<input[^>]* name="(?P<name>[^"]+)"[^>] *value="(?P<value>[^"]+)"[^>]*>)|(?:<input[^>]* value="(?P<value>[^"]+)"[^>]* name="(?P<name>[^"]+)"[^>]*>)!s'; $subject = '<input type="hidden" name="john" value="male">'; $subject .= '<input type="hidden" value="female" name="susan">'; $subject .= '<input type="hidden" name="mary" value="female">'; $subject .= '<input type="hidden" value="male" name="michael">'; $subpatterns = array(); preg_match_all($pattern, $subject, $subpatterns); This results in "Warning: preg_match_all(): Compilation failed: two named groups have the same name". The solution is to give the capture groups different names, and restructure the result yourself: $pattern = '!(?:<input[^>]* name="(?P<name1>[^"]+)"[^>] *value="(?P<value1>[^"]+)"[^>]*>)|(?:<input[^>]* value="(?P<value2>[^"]+)"[^>]* name="(?P<name2>[^"]+)"[^>]*>)!s'; $subject = '<input type="hidden" name="john" value="male">'; $subject .= '<input type="hidden" value="female" name="susan">'; $subject .= '<input type="hidden" name="mary" value="female">'; $subject .= '<input type="hidden" value="male" name="michael">'; $subpatterns = array(); preg_match_all($pattern, $subject, $subpatterns); $clean_subpatterns = array(); for($i=0; $i<count($subpatterns[0]); $i++) { $clean_subpatterns['name'][$i] = $subpatterns['name1'][$i] ? $subpatterns['name1'][$i] : $subpatterns['name2'][$i]; $clean_subpatterns['value'][$i] = $subpatterns['value1'][$i] ? $subpatterns['value1'][$i] : $subpatterns['value2'][$i]; } print_r($clean_subpatterns); Output: Array ( [name] => Array ( [0] => john [1] => susan [2] => mary [3] => michael ) [value] => Array ( [0] => male [1] => female [2] => female [3] => male ) ) This applies to PHP Version 5.1.4