JavaScript Program to Remove Empty Node from Linked List

class Node {
    constructor(value) {
        this.value = value;
        this.next = null;
    }
}

function removeEmptyNodes(head) {
    let current = head;
    let previous = null;

    while (current !== null) {
        if (current.value === null
            ||
            current.value === undefined) {

            if (previous === null) {

                head = current.next;
            } else {

                previous.next = current.next;
            }
        } else {

            previous = current;
        }


        current = current.next;
    }

    return head;
}

function printList(head) {
    while (head != null) {
        console.log(head.value + " ");
        head = head.next;
    }
    console.log("");
}


const node1 = new Node(10);
const node2 = new Node(null);
const node3 = new Node(20);
const node4 = new Node(undefined);

node1.next = node2;
node2.next = node3;
node3.next = node4;
console.log("Before Removing \n")
printList(node1);
const updatedHead = removeEmptyNodes(node1);
console.log("After Removing \n")
printList(updatedHead);

class ListNode {
    constructor(val) {
        this
            .val = val;
        this
            .next = null;
    }
}

function removeEmptyNodes(head) {
    if (!head) {
        return null;
    }

    head.next = removeEmptyNodes(head.next);

    if (!head.val) {
        return head.next;
    } else {
        return head;
    }
}

let list = new ListNode(1);
list.next = new ListNode(2);
list.next
    .next = new ListNode(null);
list.next
    .next.next = new ListNode(3);
list.next.next
    .next.next = new ListNode(null);

console.log("Original list:");
printList(list);

let result = removeEmptyNodes(list);

console.log("List after removing empty nodes:");
printList(result);

function printList(head) {
    let current = head;
    while (current !== null) {
        console.log(current.val);
        current = current.next;
    }
}