on PHP and foreach by reference

gistfile1.txt

04:46:58 tims@saw ~ $ cat test.php
<?php

$a = array(1,2,3,4);

#http://www.php.net//manual/en/control-structures.foreach.php
# "Warning Reference of a $value and the last array element remain even after the foreach loop. It is recommended to destroy it by unset()"
foreach ($a as &$b) {
        $b = $b * 2;
}

foreach ($a as $b) {
        print "$b\n";
}



04:47:02 tims@saw ~ $ php test.php
2
4
6
6
04:47:07 tims@saw ~ $ php -v
PHP 5.4.4-14+deb7u11 (cli) (built: Jun 16 2014 09:46:53)
Copyright (c) 1997-2012 The PHP Group
Zend Engine v2.4.0, Copyright (c) 1998-2012 Zend Technologies
    with Xdebug v2.2.1, Copyright (c) 2002-2012, by Derick Rethans

Same result with

PHP 5.5.13 (cli) (built: Jun 1 2014 21:27:10)
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2014 Zend Technologies
with the ionCube PHP Loader v4.6.0, Copyright (c) 2002-2014, by ionCube Ltd.

It makes complete sense when you think about it.