if ($node == NULL) { //if $node points to NULL echo "Linked List is empty"; return NULL; } while ($node->next != NULL) { echo "Node value is " . $node->value . "<br />"; $node = $node->next; //now have $node point to where $node->next is pointing to } echo "Node value is " . $node->value . "<br />"; //have it print the last node value } } $dll = new DoublyLinkedList(); //creates a new instance of the doubly linked list $dll->add(5); //should add a new node with the value of 5 $dll->add(7); //should add a new node with the value of 7 $dll->add(10); $dll->removeAllNodesWithValueOf(7); //should remove all nodes with value of 7 $dll->remove(1); //removes node of position 1 $dll->add(3); //should add a new node with the value of 3 $dll->insert(1, 100); //insert a new node of value 100 in the position 1 $dll->printValues(); //should print all the values in the doubly linked list