Description:
------------
PHP version: 5.3.13

EXAMPLE:
<?php
$a=array(
 'key'=>1
);
foreach($a as &$item)
{}

$b=array(
 'abc'=>2
);
foreach($b as &$item)
{}
var_dump($a);
?>
It will get "array(1) { ["key"]=> &int(2) } "

Buy use code like following
EXAMPLE:
<?php
$a=array(
 'key'=>1
);
foreach($a as &$item)
{}
unset($item);//unset the variable $item

$b=array(
 'abc'=>2
);
foreach($b as &$item)
{}
var_dump($a);
?>
It get the result "array(1) { ["key"]=> int(1) } ";


I think that when use refrence in foreach ,it better auto unset the refrenced ITEM and don't need use 'unset' explicitly .