Bug #53405 [Com]: accessing the iterator inside a foreach loop leads to strange results

Edit report at https://bugs.php.net/bug.php?id=53405&edit=1 ID: 53405 Comment by: chris at clowerweb dot com Reported by: jpauli@php.net Summary: accessing the iterator inside a foreach loop leads to strange results Status: Assigned Type: Bug Package: Scripting Engine problem Operating System: *nix PHP Version: 5.3.3 Assigned To: dmitry Block user comment: N Private report: N New Comment: I actually experienced something last night during Wordpress development that I believe to be related to this. <ul> <?php $posts = get_posts(); foreach($posts as $post) { setup_postdata($post); ?> <li><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></li> <?php } ?> </ul> Somehow the foreach loop was manipulating a $post (not $posts) variable in another part of the script, causing post pages to display incorrect content. Previous Comments: ------------------------------------------------------------------------ [2010-11-25 18:38:12] jpauli@php.net Description: ------------ foreach() is supposed to work on a copy of the iternal iterator. However, manipulating the iterator inside the foreach loop leads to very strange results. -> Also try to print the result of current() inside the foreach loop in the 3 use cases provided. You'll see that the iterator is some kind of manipulated by foreach Test script: --------------- $a = range('a','d'); foreach ($a as $v) { } var_dump(current($a)); $a = range('a','d'); foreach ($a as $v) { current($a); } var_dump(current($a)); $a = range('a','d'); foreach ($a as &$v) { current($a); } var_dump(current($a)); Expected result: ---------------- 'a' 'a' 'a' Actual result: -------------- false 'b' false ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=53405&edit=1