- Write a JavaScript program to delete a node from doubly Linked List?
Algorithm
Let the node to be deleted be del.
If node to be deleted is head node, then change the head pointer to
next current head.
if headnode == del then
headnode = del.nextNode
Set prev of next to del, if next to del exists.
if del.nextNode != none
del.nextNode.previousNode = del.previousNode
Set next of previous to del, if previous to del exists.
if del.previousNode != none
del.previousNode.nextNode = del.next
<script>
var head;
class Node
{
constructor(val)
{
this.data = val;
this.prev = null;
this.next = null;
}
}
function push(new_data)
{
new_Node = new Node(new_data);
new_Node.next = head;
new_Node.prev = null;
if (head != null)
head.prev = new_Node;
head = new_Node;
}
function printlist( node) {
last = null;
while (node != null) {
document.write(node.data +"");
last = node;
node = node.next;
}
document.write("<br/>");
}
function deleteNode( del) {
if (head == null || del == null) {
return;
}
if (head == del) {
head = del.next;
}
if (del.next != null) {
del.next.prev = del.prev;
}
if (del.prev != null) {
del.prev.next = del.next;
}
return;
}
push(2);
push(4);
push(8);
push(10);
document.write("Created DLL is: ");
printlist(head);
deleteNode(head);
deleteNode(head.next);
deleteNode(head.next);
document.write("Modified Linked list: ");
printlist(head);
</script>
