Modifying Arrays in PHP Closures

example1.php

<?php

$array = [];

(function() use ($array) {
    // Add an item to the array
    $array[] = 'item';
})();

var_dump($array);

/* 
 * Output:
 *
 * array(0) {
 * }
 *
 */

example2.php

<?php

$array = [];

(function() use (&$array) { // Notice the pass by reference
    // Add an item to the array
    $array[] = 'item';
})();

var_dump($array);

/* 
 * Output:
 *
 * array(1) {
 *   [0] => string(4) "item"
 * }
 *
 */