Description:
------------
Foreach an array by reference will change the last value (previous).

Test script:
---------------
<?php

$array = [
	['a' => 'aa'],
	['b' => 'bb'],
	['c' => 'cc'],
	['d' => 'dd'],
	['e' => 'ee'],
	['f' => 'ff'],
];

foreach ($array as & $item) {
}

var_dump($array);
/*

here will output:

array(6) {
  [0]=>
  array(1) {
    ["a"]=>
    string(2) "aa"
  }
  [1]=>
  array(1) {
    ["b"]=>
    string(2) "bb"
  }
  [2]=>
  array(1) {
    ["c"]=>
    string(2) "cc"
  }
  [3]=>
  array(1) {
    ["d"]=>
    string(2) "dd"
  }
  [4]=>
  array(1) {
    ["e"]=>
    string(2) "ee"
  }
  [5]=>
  &array(1) {
    ["f"]=>
    string(2) "ff"
  }
}

*/

echo '=====================================', PHP_EOL;

foreach ($array as $item) {
	var_dump($item);
}

/*
array(1) {
  ["a"]=>
  string(2) "aa"
}
array(1) {
  ["b"]=>
  string(2) "bb"
}
array(1) {
  ["c"]=>
  string(2) "cc"
}
array(1) {
  ["d"]=>
  string(2) "dd"
}
array(1) {
  ["e"]=>
  string(2) "ee"
}
array(1) {
  ["e"]=>
  string(2) "ee" // => this one was changed.
}
*/