<?php/* * Examples of DoublyLinkedList */$obj = new SplDoublyLinkedList();// Check wither linked list is emptyif ($obj->isEmpty()){ echo "Adding nodes to Linked List<br>"; $obj->push(2); $obj->push(3); echo "Adding the node at beginning of doubly linked list <br>"; $obj->unshift(10);}echo "<br>Our Linked List:";print_r($obj);$curr = $obj->current(); // this will return NULL as we have not set initial node.echo "<br> Rewinding the position so that current node points to first node ";$obj->rewind(); echo "<br>Current node of the linked list:";echo $obj->current(); // this will print first node of the linked list.echo "<br>Moving to Next node:";$obj->next();echo "<br>Printing the next node:";echo $obj->current();?>