Welcome to the Node.js Guide! Whether you're new to server-side JavaScript or looking to deepen your understanding, this tutorial will walk you through the essentials of building scalable applications with Node.js.

🚀 What is Node.js?

Node.js is an open-source runtime environment that allows developers to run JavaScript on the server. It's built on Chrome's V8 JavaScript engine and is perfect for creating real-time applications, APIs, and command-line tools.

  • Key Features:
    • Asynchronous and event-driven
    • Non-blocking I/O operations
    • Single-threaded with multi-threaded capabilities via worker_threads
    • Rich ecosystem of packages (npm)
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📦 Getting Started

  1. Install Node.js: Head to https://nodejs.org and download the latest LTS version.
  2. Verify Installation: Run node -v and npm -v in your terminal to check versions.
  3. Create a Project: 
    mkdir my-node-app  
cd my-node-app  
npm init -y

📚 Core Concepts

📌 1. Modules and require()

Node.js uses modules to organize code. For example: 

const http = require('http');  
http.createServer((req, res) => {  
  res.end('Hello, Node.js!');  
}).listen(3000);

📌 2. Asynchronous Programming

Node.js excels at handling asynchronous tasks with callbacks, Promises, and async/await.

  • Use fs.promises.readFile() for non-blocking file operations.
  • Explore the Node.js Async Guide for deeper insights.
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📌 3. Streams and Buffers

Streams are efficient for handling large data. For example: 

const fs = require('fs');  
const readStream = fs.createReadStream('largefile.txt');  
readStream.on('data', (chunk) => {  
  console.log(chunk.toString());  
});

🌐 Building APIs with Express

Express.js is a popular framework for Node.js. Start by installing it: 

npm install express

Then create a simple server: 

const express = require('express');  
const app = express();  

app.get('/', (req, res) => {  
  res.send('Welcome to the API!');  
});  

app.listen(3000, () => {  
  console.log('Server running on http://localhost:3000');  
});

🧠 Best Practices

  • Use npm: Always manage dependencies via package.json.
  • Avoid Blocking: Keep long-running tasks in separate processes.
  • Security: Use express-rate-limit to prevent abuse.
  • Testing: Leverage Mocha or Jest for unit tests.

For more advanced topics, check out our Node.js Advanced Features guide.

📌 Next Steps

Let me know if you need help with specific projects or want to dive into a particular topic! 🌟