Linked List Implementation

A comprehensive JavaScript implementation of the Linked List data structure with full test coverage and practical examples.

📖 Table of Contents

• Linked List Implementation
  • 📖 Table of Contents
  • 🎯 About
  • ✨ Features
  • 📋 Prerequisites
  • 🔧 Installation
    • 1. Clone the repository
    • 2. Install dependencies (optional)
  • 💻 Usage
    • Basic Example
    • Running the Demo
    • Method Examples
  • 🧪 Testing
  • 🛠️ Built With
  • 📄 License

🎯 About

This project implements a Linked List data structure in JavaScript as part of The Odin Project Full Stack JavaScript curriculum. While JavaScript arrays are dynamic and flexible, understanding linked lists provides a solid foundation for learning more complex data structures like graphs and binary trees.

A linked list is a linear collection of data elements called nodes, where each node contains:

• A value (the data)
• A pointer to the next node in the sequence

This implementation uses ES6 modules and is compatible with Node.js v22+.

Key Concepts:

• Dynamic data structure that grows and shrinks at runtime
• Efficient insertion and deletion at any position
• No need for contiguous memory allocation
• Foundation for understanding more complex data structures

✨ Features

• Core Operations - append, prepend, insert, remove, and traverse nodes
• Index-based Access - retrieve nodes by position with at(index)
• Search Operations - find values and their indices with contains() and findIndex()
• Flexible Insertion - insert multiple values at any index with insertAt()
• String Representation - visualize the list with toString()
• ES6 Module Support - modern JavaScript syntax with import/export
• Comprehensive Examples - practical usage demonstrations in main.js
• Error Handling - proper boundary checks and error messages

📋 Prerequisites

Before you begin, ensure you have met the following requirements:

• Node.js >= 22.0.0 - Download here
• Git - For version control
• A code editor (VS Code, Sublime Text, etc.)

🔧 Installation

1. Clone the repository

git clone https://github.com/top-submissions/fullstackjs-linked-list.git
cd fullstackjs-linked-list

2. Install dependencies (optional)

This project has no external dependencies and runs with vanilla JavaScript.

# If you add testing frameworks or linters later
npm install

💻 Usage

Basic Example

import { LinkedList } from './LinkedList.js';

// Create a new linked list
const list = new LinkedList();

// Add elements
list.append("dog");
list.append("cat");
list.prepend("bird");

// Display the list
console.log(list.toString());
// Output: ( bird ) -> ( dog ) -> ( cat ) -> null

// Get list size
console.log(list.size()); // 3

// Access elements
console.log(list.at(1)); // "dog"
console.log(list.head()); // "bird"
console.log(list.tail()); // "cat"

Running the Demo

Execute the test file to see the linked list in action:

node main.js

Method Examples

// Check if value exists
list.contains("dog"); // true

// Find index of value
list.findIndex("cat"); // 2

// Insert at specific position
list.insertAt(1, "hamster", "snake");
console.log(list.toString());
// ( bird ) -> ( hamster ) -> ( snake ) -> ( dog ) -> ( cat ) -> null

// Remove by index
list.removeAt(2);
console.log(list.toString());
// ( bird ) -> ( hamster ) -> ( dog ) -> ( cat ) -> null

// Remove first element
list.pop(); // Returns "bird"

🧪 Testing

Test your implementation by running:

node main.js

Expected output:

( dog ) -> ( cat ) -> ( parrot ) -> ( hamster ) -> ( snake ) -> ( turtle ) -> null

You can add your own test cases in main.js or create additional test files in the examples/ directory.

🛠️ Built With

• JavaScript ES6+ - Modern JavaScript features (classes, modules)
• Node.js - JavaScript runtime environment

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

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Made with ❤️ for The Odin Project