🚀 Node.js Basics & Core Modules

This repository contains beginner-friendly examples of important Node.js concepts such as:

• OS Module
• Path Module
• File System (FS)
• HTTP Server
• Routing
• Asynchronous Programming
• Callback Functions
• TCP Server

Perfect for learning backend development with Node.js.

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📂 Project Structure

📁 nodejs-learning
 ┣ 📄 index.js
 ┣ 📄 README.md

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⚡ Getting Started

📥 Clone Repository

git clone https://github.com/your-username/nodejs-learning.git

📦 Install Node.js

Download and install Node.js from:

https://nodejs.org/

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▶️ Run the Project

node index.js

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📚 Topics Covered

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1️⃣ OS Module

The OS module provides information about the operating system.

Example

const os = require('os');

console.log(os.version());
console.log(os.freemem());
console.log(os.homedir());
console.log(os.hostname());

Features

• Get OS version
• Get free memory
• Get home directory
• Get system hostname

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2️⃣ Path Module

The Path module helps handle file and directory paths.

Example

const path = require('path');

const filepath = 'C:\\Users\\file.txt';

console.log(path.basename(filepath));
console.log(path.dirname(filepath));
console.log(path.extname(filepath));

Methods Used

Method	Description
basename()	Returns file name
dirname()	Returns folder path
extname()	Returns file extension

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3️⃣ File System Module (FS)

Used for creating, reading, updating, and deleting files.

Create File

const fs = require('fs');

fs.writeFile('Node.txt', 'This is Node js File', (err) => {
    if(err) throw err;
    console.log("File Created");
});

Read File

fs.readFile('Node.txt', 'utf-8', (err, data) => {
    console.log(data);
});

Delete File

fs.unlink('Node.txt', (err) => {
    console.log("File deleted");
});

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4️⃣ HTTP Server

Node.js can create web servers using the HTTP module.

Example

const http = require('http');

const server = http.createServer((req, res) => {
    res.end("Server Running");
});

server.listen(4000, () => {
    console.log("Server started");
});

Output

http://localhost:4000

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5️⃣ HTTP Routing

Routing allows different responses for different URLs.

Example

if(url == '/'){
   res.end("Home Page");
}
else if(url == '/contact'){
   res.end("Contact Page");
}
else{
   res.end("404 Not Found");
}

Routes

Route	Description
/	Home Page
/contact	Contact API
/product	Product API

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6️⃣ Asynchronous Programming

Node.js executes asynchronous operations without blocking the main thread.

Example

console.log("Program 1");

setTimeout(() => {
   console.log("Program 2");
}, 2000);

console.log("Program 3");

Concepts

• Event Loop
• Non-blocking code
• Timers
• Async execution

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7️⃣ Callback Functions

A callback is a function passed into another function.

Example

function Employee(name, callback){
   console.log(name);

   callback();
}

Employee("Sam", function(){
   console.log("Welcome");
});

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8️⃣ TCP Server

TCP server communication using Node.js Net module.

Example

import net from "node:net";

const server = net.createServer();

server.listen(4000, () => {
   console.log("TCP Server Started");
});

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🛠 Technologies Used

• Node.js
• JavaScript
• HTTP Module
• File System Module
• TCP Networking

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📖 Learning Outcomes

After completing this project, you will understand:

✅ Core Node.js modules
✅ Server creation
✅ File handling
✅ Routing
✅ Asynchronous programming
✅ Callback functions
✅ TCP communication

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🌟 Future Improvements

• Add Express.js
• Add MongoDB
• Build REST APIs
• Authentication System
• Real-time Chat Application

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🤝 Contributing

Contributions are welcome.

1. Fork repository
2. Create new branch
3. Commit changes
4. Push branch
5. Create Pull Request

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📜 License

This project is licensed under the MIT License.

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👨‍💻 Author

Fulbabu Islam

• 🌐 Portfolio: https://fulbabu.dev/
• 💻 GitHub: https://github.com/fulbabu-t
• 🔗 LinkedIn: https://www.linkedin.com/in/fulbabu-islam-96a9ba2ba