If I iterate through an array twice, once by reference and then by value, PHP will overwrite the last value in the array if I use the same variable name for each loop. This is best illustrated through an example:

$array = range(1,5);
foreach($array as &$element)
{
  $element *= 2;
}
print_r($array);
foreach($array as $element) { }
print_r($array);

Output:

Array ( [0] => 2 [1] => 4 [2] => 6 [3] => 8 [4] => 10 )

Array ( [0] => 2 [1] => 4 [2] => 6 [3] => 8 [4] => 8 )

Note that I am not looking for a fix, I am looking to understand why this is happening. Also note that it does not happen if the variable names in each loop are not each called $element, so I'm guessing it has to do with $element still being in scope and a reference after the end of the first loop.