JavaScript Exercises: Get index of an given element in a Singly Linked list

JavaScript Singly Linked List: Exercise-17 with Solution

Write a JavaScript program to get the index of an element in a Singly Linked list.

Sample Solution:

JavaScript Code:

class Node {
    constructor(data) {
        this.data = data;
        this.next = null;               
class SinglyLinkedList {
    constructor(Head = null) {
        this.Head = Head;
    let node = this.Head;
        this.Head = newNode;
    while (node.next) {
        node = node.next;
    node.next = newNode;
 index_of(el) {
  let index = 0;
  let node = this.Head; 
  while (node) {
    if (node.data === el) {
      return index;
    node = node.next;
  return -1;
    let node = this.Head;
    var str = ""
    while (node) {
        str += node.data + "->";
        node = node.next;
    str += "NULL"
let numList = new SinglyLinkedList();
numList.add(new Node(12));
numList.add(new Node(13));
numList.add(new Node(14));
numList.add(new Node(15));
numList.add(new Node(14));
numList.add(new Node(16));
console.log("Singly Linked list:")
result = numList.index_of(12);
console.log("Index of 12 in the said link list: "+result);
result = numList.index_of(13);
console.log("Index of 13 in the said link list: "+result);
result = numList.index_of(14);
console.log("Index of 14 in the said link list: "+result);
result = numList.index_of(16);
console.log("Index of 16 in the said link list: "+result);

Sample Output:

Singly Linked list:
Index of 12 in the said link list: 0
Index of 13 in the said link list: 1
Index of 14 in the said link list: 2
Index of 16 in the said link list: 5


Flowchart: JavaScript Exercises: Convert a Singly Linked list into an array.

Live Demo:

See the Pen javascript-singly-linked-list-exercise-17 by w3resource (@w3resource) on CodePen.

Improve this sample solution and post your code through Disqus

Singly Linked List Previous: Convert a Singly Linked list into a string.
Singly Linked List Next: Check if an element is present in the Singly Linked list.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.

Follow us on Facebook and Twitter for latest update.

JavaScript: Tips of the Day

Initialize an Array with Values

We can use the Array constructor with the fill method to create an array and fill it with items. For instance, we can write:


to create an array with 20 empty slots, then fill the slots with 10.

Ref: https://bit.ly/3mp5NgH