PHP 7 Data Structures and Algorithms

Displaying the list forward

Doubly linked lists gives us the opportunity to display the list in both directions. So far, we have seen that we can display the list in a unidirectional way while working in a singly linked list. Now, we will see the list from both directions. Here is the code used to display the list forward:

    public function displayForward() {         echo "Total book titles: " . $this->_totalNode . "\n";         $currentNode = $this->_firstNode;         while ($currentNode !== NULL) {             echo $currentNode->data . "\n";             $currentNode = $currentNode->next;         }     }