- unserialize: documentation ( source)
- print_r: documentation ( source)
- serialize: documentation ( source)
<?php
$foo = null;
echo serialize(['brand_user_id' => 123, 'last_login_dt' => $foo ? $foo->format('Y-m-d') : null]);
print_r(unserialize('a:2:{s:13:"brand_user_id";i:123;s:13:"last_login_dt";N;}'));