note 102552 added to function.usort

To sort a multidimensional array (such as is returned from database query) by the values in $array[foo][$key] e.g. <?php /** Potential pitfall if there is already a key of '__________' * in the subarrays. Not likely I hope! * ------------------------------------------------------------- */ function array_sort_by_subval(&$array, $key) { foreach($array as &$v) { $v['__________'] = $v[$key]; } usort($array, 'sort_by_underscores'); foreach($array as &$v) { unset($v['__________']); } } function sort_by_underscores($a, $b) { if($a['__________'] == $b['__________']) return 0; if($a['__________'] < $b['__________']) return -1; return 1; } $n = array(array('a' => 0, 'b' => 7, 'c' => 2), array('a' => 4, 'b' => 1, 'c' => 3), array('a' => 7, 'b' => 3, 'c' => 1)); array_sort_by_subval($n, 'b'); ?> The array $n will now be: array(array('a' => 4, 'b' => 1, 'c' => 3), array('a' => 7, 'b' => 3, 'c' => 1), array('a' => 0, 'b' => 7, 'c' => 2)) ---- Server IP: 69.147.83.197 Probable Submitter: 86.12.188.97 (proxied: 127.0.0.1) ---- Manual Page -- http://www.php.net/manual/en/function.usort.php Edit -- https://master.php.net/note/edit/102552 Del: integrated -- https://master.php.net/note/delete/102552/integrated Del: useless -- https://master.php.net/note/delete/102552/useless Del: bad code -- https://master.php.net/note/delete/102552/bad+code Del: spam -- https://master.php.net/note/delete/102552/spam Del: non-english -- https://master.php.net/note/delete/102552/non-english Del: in docs -- https://master.php.net/note/delete/102552/in+docs Del: other reasons-- https://master.php.net/note/delete/102552 Reject -- https://master.php.net/note/reject/102552 Search -- https://master.php.net/manage/user-notes.php