How can the PHP code be modified to properly handle array values when transferring them between pages in a multi-step form?

When transferring array values between pages in a multi-step form, the array values need to be serialized before passing them as a query parameter in the URL. This ensures that the array values are properly encoded and decoded when moving between pages. To handle array values correctly, you can use the `serialize()` function to serialize the array before passing it as a query parameter and the `unserialize()` function to deserialize it on the receiving page.

// Serialize the array before passing it as a query parameter
$serializedArray = serialize($array);

// Pass the serialized array as a query parameter in the URL
header("Location: next_page.php?data=" . urlencode($serializedArray));
exit;

// On the receiving page, unserialize the array
$receivedArray = unserialize(urldecode($_GET['data']));