[Php-avanzado] Problema foreach

[Mauro Giuffo]

Encontre esto en php.net:

As of PHP 5, you can easily modify array's elements by preceding
$value with &. This will assign reference instead of copying the
value.

<?php
$arr = array(1, 2, 3, 4);
foreach ($arr as &$value) {
    $value = $value * 2;
}
// $arr is now array(2, 4, 6, 8)
unset($value); // break the reference with the last element
?>

aparentemente hay que agregar un & antes de la variable que va a
contener el valor para poder modificarlo

Saludos