note 75304 added to control-structures.foreach

The documentation states foreach uses a copy of an array unless it's referenced. The example uses foreach ($arr as &$element) { if (condition) { change element; } } One reason never to modify array values directly in a foreach: $arr = array (1,3,5,8,11,19); foreach ($arr as $key=>$value) { if ($value %2 != 0) $arr['oddcount'] += 1; } echo $arr['oddcount']; //output: 5, as expected. But: $arr = array (1,3,5,8,11,19); $ref = &$arr; // create a reference, outside the loop. foreach ($arr as $key=>$value) { if ($value %2 != 0) $arr['oddcount'] += 1; } echo $arr['oddcount']; //output: 6 !!! Since it isn't always clear where in the code a reference is made to the array, the behaviour of any foreach loop modifying array elements directly becomes unpredictable. If you want to change array values inside a foreach, create your own array and copy it back after the loop. (Thanks to Gosha Bine.) ---- Server IP: 83.137.20.120 Probable Submitter: 88.211.177.163 ---- Manual Page -- http://www.php.net/manual/en/control-structures.foreach.php Edit -- https://master.php.net/note/edit/75304 Del: integrated -- https://master.php.net/note/delete/75304/integrated Del: useless -- https://master.php.net/note/delete/75304/useless Del: bad code -- https://master.php.net/note/delete/75304/bad+code Del: spam -- https://master.php.net/note/delete/75304/spam Del: non-english -- https://master.php.net/note/delete/75304/non-english Del: in docs -- https://master.php.net/note/delete/75304/in+docs Del: other reasons-- https://master.php.net/note/delete/75304 Reject -- https://master.php.net/note/reject/75304 Search -- https://master.php.net/manage/user-notes.php