note 89918 added to function.array-multisort

I was (as near everyone here :-) looking to sort 2-dimensional arrays by certain fields in the associative sub-arrays. What I didn't like about the documentation examples is that you need to loop through the input array to create sub arrays first, then use those in the function call. "php a-t-the-r-a-t-e chir.ag" (http://www.php.net/manual/en/function.array-multisort.php#60401) wrote a quite cunning wrapper function, I rewrote it slightly, changing variable names and adding comments (for my sanity :-) mostly. One snag I found: the input array is passed to array_multisort as last argument, but the changed array is not the one that is returned. Passing it by reference fixed that. This seems to be caused by the whole thing sitting inside the call_user_func_array, as shown below. <?php $points = array(1, 5, 2, 2); $names = array('peter', 'mike', 'john Zoo', 'john Ab'); $source = array ( array ( 'points' => 1, 'name' => 'Peter'), array ( 'points' => 5, 'name' => 'Mike'), array ( 'points' => 2, 'name' => 'John Zoo'), array ( 'points' => 2, 'name' => 'John Ab') ); call_user_func_array('array_multisort', array($points, SORT_DESC, SORT_NUMERIC, $names, SORT_ASC, SORT_STRING, $source)); // doesn't work print_r($source); call_user_func_array('array_multisort', array($points, SORT_DESC, SORT_NUMERIC, $names, SORT_ASC, SORT_STRING, &$source)); // works! print_r($source); // Call like arrayColumnSort('points', SORT_DESC, SORT_NUMERIC, 'name', SORT_ASC, SORT_STRING, $source); // Slightly adapted from http://www.php.net/manual/en/function.array-multisort.php#60401 // arrayColumnSort(string $field, [options, ], string $field2, [options, ], .... , $array) / //____________________ // arrayColumnSort() / function arrayColumnSort() { $args = func_get_args(); $array = array_pop($args); if (! is_array($array)) return false; // Here we'll sift out the values from the columns we want to sort on, and put them in numbered 'subar' ("sub-array") arrays. // (So when sorting by two fields with two modifiers (sort options) each, this will create $subar0 and $subar3) foreach($array as $key => $row) // loop through source array foreach($args as $akey => $val) // loop through args (fields and modifiers) if(is_string($val)) // if the arg's a field, add its value from the source array to a sub-array ${"subar$akey"}[$key] = $row[$val]; // $multisort_args contains the arguments that would (/will) go into array_multisort(): sub-arrays, modifiers and the source array $multisort_args = array(); foreach($args as $key => $val) $multisort_args[] = (is_string($val) ? ${"subar$key"} : $val); $multisort_args[] = &$array; // finally add the source array, by reference call_user_func_array("array_multisort", $multisort_args); return $array; } ?> ---- Server IP: 83.137.20.135 Probable Submitter: 94.212.43.63 ---- Manual Page -- http://www.php.net/manual/en/function.array-multisort.php Edit -- https://master.php.net/note/edit/89918 Del: integrated -- https://master.php.net/note/delete/89918/integrated Del: useless -- https://master.php.net/note/delete/89918/useless Del: bad code -- https://master.php.net/note/delete/89918/bad+code Del: spam -- https://master.php.net/note/delete/89918/spam Del: non-english -- https://master.php.net/note/delete/89918/non-english Del: in docs -- https://master.php.net/note/delete/89918/in+docs Del: other reasons-- https://master.php.net/note/delete/89918 Reject -- https://master.php.net/note/reject/89918 Search -- https://master.php.net/manage/user-notes.php