Data Structure in JavaScript

Linked List in JavaScript

What is a Data Structure?

In computer science, a data structure is a data organization, management, and storage format that is usually chosen for efficient access to data.

What is Linked List?

🧠 A linked list is a linear collection of data elements whose order is not given by their physical placement in memory.

A node(element in Linked List) has its data and reference to the next item

Let’s Break it Down🤩

What are the types of Linked List?

1. Singly LinkedList
2. Doubly Linked List
3. Circular Linked List

Picture speaks louder than words:👇🏻

What is Node in a Linked List?

A linked List is a collection of connected nodes where the node is something that has the data part as well as the link to the next node.

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

How to implement Linked List?

In a Linked list, mostly what we know is the head node; from the head node, we can get the other remaining nodes. Head node is the first node in a linked list. We can also maintain a tail node in order to make operations faster.

class LinkedList{
constructor(){
this.head=null;
this.tail=null;
}
}

We have our Node as well as LinkedList Class.

Now let’s begin the actual fun by adding data to our linked list.

Let’s add a new Node to our Empty LinkedList.

Add a single node

✓ This is how you add a single node to LinkedList

✓ Let’s make a function to add a node at the head

Add a new node at the head

While adding a new node, the new Node should point to the current head Node and then the head should point to the new node

class LinkedList{
constructor(){
this.head=null;
this.tail=null;
}
addElementatHead(key) {
let node = new Node(key);
if (this.head == null) {
this.head = node;
return;
} else {
node.next = this.head;
this.head = node;
}
}
}

Add a new node at the End Of a Linked List

//inside class
addElemenAtEnd(key) {
let node = new Node(key);
if (this.head == null) {
this.head = node;
return;
} else {
let temp = this.head;
while (temp.right !== undefined) {
temp = temp.right;
}
temp.right = node;
}

Traverse through Linked List

//inside class linkedlist as a method
traverse() {
let temp = this.head;
// console.log(temp.next);
while (temp?.key != undefined) {
console.log(temp.key);
temp = temp.next;
}
}

Remove at Head

removeathead(){
let temp = this.head;
this.head = temp.next;
temp = null;
}

Hope this detailed thread was useful. Follow me on Medium as well as on my Twitter handle Adarsh Gupta for more content around JavaScript, Web Development, DSA, and more.

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Happy Learning, Happy Coding