#29992 [Com]: foreach by reference corrupts the array

ID: 29992 Comment by: yaroukh at email dot cz Reported By: fletch at pobox dot com Status: Open Bug Type: Zend Engine 2 problem Operating System: linux PHP Version: 5.0.1 New Comment: I believe the problem I'm gonna describe here has the same roots as the one fletch has described ... Try this: <? class ArrayWrapper { protected $slots; public function __construct($slots = Array()) { $this->slots =& $slots; } public function & getSlot($idx) { if(IsSet($this->slots[$idx])) return $this->slots[$idx]; return null; } public function getLength() { return Count($this->slots); } } // fill the array and create object { $slots = Array( 'zero', 'one', 'two', 'three', 'four' ); $aw = new ArrayWrapper($slots); // } // output A var_dump($aw); // iteration 1 for($idx = 0; $idx < $aw->getLength(); $idx++) $aw->getSlot($idx); // output B; everything is OK var_dump($aw); // iteration 2 for($idx = 0; $idx < $aw->getLength(); $idx++) if($aw->getSlot($idx)) { } // output C; elements have been changed to references var_dump($aw); ?> As you can see in output "C" the second iteration altered elements of the array - the elements have been turned into references. (Or did I get the ampersand-sign wrong?) The problem is that I loose control over the REAL objects and the elements get changed unreasonably later in the script. I kind of understand what's the diference between getSlot() and getSlot() used within an if-loop (I guess the scope created by if-loop makes the difference), but I'm not sure this difference entitles PHP to alter my array. Can anyone explain this to me? Is it a bug or a regular behaviour? Previous Comments: ------------------------------------------------------------------------ [2004-09-06 08:04:28] fletch at pobox dot com changed the summary ------------------------------------------------------------------------ [2004-09-06 05:54:50] fletch at pobox dot com Description: ------------ foreach with a reference seems to corrupt the last element in an array Reproduce code: --------------- <?php $array = array(1,2,3); foreach( $array as &$item ) { } print_r( $array ); foreach( $array as $item ) { } print_r( $array ); ?> Expected result: ---------------- Array ( [0] => 1 [1] => 2 [2] => 3 ) Array ( [0] => 1 [1] => 2 [2] => 3 ) Actual result: -------------- Array ( [0] => 1 [1] => 2 [2] => 3 ) Array ( [0] => 1 [1] => 2 [2] => 2 ) ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=29992&edit=1