Node.js

Definition

Node.js is an open-source, cross-platform JavaScript runtime environment that executes JavaScript code outside of a web browser. Built on Chrome's V8 JavaScript engine, Node.js enables developers to use JavaScript for server-side scripting, allowing for the development of scalable network applications and backend services.

Key Features

• Event-Driven: Uses an event-driven, non-blocking I/O model
• Single-Threaded: Uses a single-threaded event loop for handling requests
• Cross-Platform: Runs on Windows, macOS, and Linux
• NPM Ecosystem: Access to the largest package repository
• Fast Execution: Built on Google's V8 JavaScript engine
• Scalable: Ideal for building scalable network applications

Example Code

// Simple HTTP Server
const http = require('http');

const server = http.createServer((req, res) => {
  res.writeHead(200, { 'Content-Type': 'text/plain' });
  res.end('Hello World from Node.js!');
});

server.listen(3000, () => {
  console.log('Server running on port 3000');
});

// Express.js Framework Example
const express = require('express');
const app = express();

app.get('/', (req, res) => {
  res.json({ message: 'Hello from Express!' });
});

app.listen(3000, () => {
  console.log('Express server running on port 3000');
});

Popular Frameworks & Libraries

• Express.js: Minimal and flexible web application framework
• Koa.js: Next-generation web framework by Express team
• NestJS: Progressive Node.js framework for building scalable applications
• Fastify: Fast and low overhead web framework
• Socket.io: Real-time bidirectional event-based communication
• Mongoose: MongoDB object modeling for Node.js

Career Impact

Learning Path

1. Master JavaScript fundamentals and ES6+ features
2. Understand asynchronous programming (callbacks, promises, async/await)
3. Learn Node.js core modules (fs, http, path, os)
4. Practice with Express.js framework
5. Learn database integration (MongoDB, PostgreSQL)
6. Understand authentication and security best practices
7. Explore testing frameworks (Jest, Mocha) and deployment