Maybe the basic usage is like this i think..
$a = new \SplDoublyLinkedList;
if ($a instanceof \SplDoublyLinkedList) {
$a->add(0, 'Paulus');
$a->add(1, 'Gandung');
$a->add(2, 'Prakosa');
// then, iterate over that because \SplDoublyLinkedList
// is implementing \Iterator interface.
foreach ($a as $value) {
echo sprintf("%s\n", $value);
}
}