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Bug #64066 foreach with reference alter variable
Submitted: 2013-01-24 23:49 UTC Modified: 2013-01-25 00:12 UTC
From: w at ndrille dot fr Assigned:
Status: Not a bug Package: Testing related
PHP Version: 5.4.11 OS: Linux and Windows
Private report: No CVE-ID: None
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 [2013-01-24 23:49 UTC] w at ndrille dot fr 
Description:
------------
When we use foreach with reference and use foreach again with the same variable 
without doing any action, php will alter array: The last value is doubled

Test script:
---------------
<?php
$a = array(1,2,3);
$z = $a;

foreach ($a as &$b){}
foreach ($a as $b){}

print_r($a);

if ($a != $z)
	print('bug');
?>

Expected result:
----------------
Array ( [0] => 1 [1] => 2 [2] => 3 )

Actual result:
--------------
Array ( [0] => 1 [1] => 2 [2] => 2 ) bug

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 [2013-01-25 00:12 UTC] tyrael@php.net
-Status: Open +Status: Not a bug
 [2013-01-25 00:12 UTC] tyrael@php.net 
Sorry, but your problem does not imply a bug in PHP itself.  For a
list of more appropriate places to ask for help using PHP, please
visit http://www.php.net/support.php as this bug system is not the
appropriate forum for asking support questions.  Due to the volume
of reports we can not explain in detail here why your report is not
a bug.  The support channels will be able to provide an explanation
for you.

Thank you for your interest in PHP.

It is a documented behavior:
http://php.net/manual/en/control-structures.foreach.php
"Reference of a $value and the last array element remain even after the foreach 
loop. It is recommended to destroy it by unset()."
 
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