Simple Linked List Implementation in JavaScript

What is a Linked List?

A Linked List is a linear data structure made up of nodes.
Each node has two parts:

Data → stores the actual value.
Next Pointer → points to the next node in the list.

The first node is called the head.
If the list is empty, the head is NULL.

Simple Example in JavaScript

Here’s a basic implementation of a linked list with three nodes:

// Define a Node class
class Node {
    constructor(value) {
        this.data = value;   // store the value
        this.next = null;    // pointer to the next node
    }
}
 
// Create nodes
let head = new Node(5);       // first node (head)
let second = new Node(15);    // second node
let third = new Node(25);     // third node
 
// Link nodes together
head.next = second;
second.next = third;
 
// Function to print the linked list
function printList(node) {
    let current = node;
    let result = "";
    while (current !== null) {
        result += current.data + " --> ";
        current = current.next;
    }
    result += "NULL";  // marks the end of the list
    console.log(result);
}
 
// Print the linked list
printList(head);

Output

5 --> 15 --> 25 --> NULL

How It Works (Easy Explanation)

Each Node stores a value (data) and a link to the next node (next).
We created three nodes with values 5, 15, 25.
We connected them using the next pointer.
The printList function starts from the head and keeps following the next pointer until the end (NULL).

So the linked list looks like this:

5 → 15 → 25 → NULL

Introduction Applications of Linked List