Introduction to Node Manipulation in Javascript

In Javascript, nodes are often used to represent linked lists. In this guide, we will introduce how to manipulate nodes in linked lists, including adding and deleting nodes.

Adding a Node

To add a node to the beginning of a linked list, we can create a new node temp with the desired value and set its next pointer to the current head node. We then set the next pointer of the head node to temp and set the prev pointer of the next node to temp.

let temp = new Node(6, head, head.getNext());
head.setNext(temp);
temp.getNext().setPrev(temp);

Here, head is the current head node of the linked list. We create a new node with value 6 and set its next pointer to the current head node's next pointer. We then set the next pointer of the head node to temp, effectively adding temp to the beginning of the linked list. Finally, we set the prev pointer of the next node after temp to temp.

Deleting a Node

To delete a node from the end of a linked list, we can set the prev pointer of the tail node to the node before it, and set the next pointer of that node to the tail node. We then set the prev pointer of the tail node's previous node to the tail node's previous node.

let temp1 = tail.getPrev();
tail.setPrev(temp1.getPrev());
temp1.getPrev().setNext(tail);

Here, tail is the current tail node of the linked list. We create a new node temp1 that points to the node before the tail node. We then set the prev pointer of the tail node to temp1's prev pointer, and set the next pointer of that node to tail. This effectively removes temp1 from the list. Finally, we set the prev pointer of temp1's previous node to tail, completing the removal of temp1 from the list.

In summary, node manipulation is an essential skill for managing linked lists in Javascript. With these techniques, you can add and delete nodes with ease.