Helper function for create blank array by number of each dimension.

createBlankArray.php

<?php
/**
 * Create blank array by number
 *
 * @param int Number of members in each dimension
 * @return array
 */
function createBlankArray()
{
    $dimensions = func_get_args();
    $base = null;
    while ($amount = array_shift($dimensions)) {
        $callback = function(&$item) use ($amount) {
            $item = [];
            for ($i = 0; $i < $amount; $i++) {
                $item[] = null;
            }
        };

        if (is_array($base)) {
            array_walk_recursive($base, $callback);
        } else {
            $callback($base);
        }
    }
    return $base;
}

/**
 * Usage:
 * $output = createBlankArray(3, 1, 4, 2);
 * 
 * Output:
 * array:3 [▼
 *   0 => array:1 [▼
 *     0 => array:4 [▼
 *       0 => array:2 [▼
 *         0 => null
 *         1 => null
 *       ]
 *       1 => array:2 [▼
 *         0 => null
 *         1 => null
 *       ]
 *       2 => array:2 [▶]
 *       3 => array:2 [▶]
 *     ]
 *   ]
 *   1 => array:1 [▶]
 *   2 => array:1 [▶]
 * ]
*/