Description:
------------
I've seen this on a reddit post, I thought it would be nice to put it here.

There's a weird behaviour, when looping two times in an arrow, using referenced values : the first loop will change the value of the last element, with the same value as the previous one. See the example. 

I've tested this with strings and arrays.

This behaviour is present since forever (including 7.0 RC1).

Test script:
---------------
<?php
// Strings
$data = array('a','b','c','d');
foreach ($data as $k => &$value) {}
foreach ($data as $value) { 
    echo $value;
}
// Arrays
$data = array(array(1,2),array(3,4),array(5,6),array(7,8));
foreach ($data as $k => &$value) {}
foreach ($data as $value) {
    var_dump($value);
}

Expected result:
----------------
abcd
array(2){[0]=> int(1)[1]=> int(2)}
array(2){[0]=> int(3)[1]=> int(4)}
array(2){[0]=> int(5)[1]=> int(6)}
array(2){[0]=> int(7)[1]=> int(8)}

Actual result:
--------------
abcc
array(2){[0]=> int(1)[1]=> int(2)}
array(2){[0]=> int(3)[1]=> int(4)}
array(2){[0]=> int(5)[1]=> int(6)}
array(2){[0]=> int(5)[1]=> int(6)}