Installing Node.js

  1. Download the LTS version from https://nodejs.org/
  2. Run the installer for your OS
  3. Verify installation:
  node --version   # e.g. v20.x.x
npm --version    # e.g. 10.x.x

Version Management (Optional)

Use nvm (Node Version Manager) to switch between Node versions:

  # Install nvm (see https://github.com/nvm-sh/nvm)
nvm install 20
nvm use 20

Project Structure 

  my-api/
├── package.json
├── index.js
├── src/
│   └── routes/
└── node_modules/   (auto-generated)

Initialize a Project 

  mkdir my-api && cd my-api
npm init -y

This creates package.json:

  {
  "name": "my-api",
  "version": "1.0.0",
  "main": "index.js",
  "scripts": {
    "start": "node index.js",
    "dev": "node --watch index.js"
  }
}

Your First HTTP Server

Create index.js:

  const http = require('http');

const server = http.createServer((req, res) => {
    res.writeHead(200, { 'Content-Type': 'application/json' });
    res.end(JSON.stringify({
        message: 'Hello from Node.js API!',
        path: req.url,
        method: req.method
    }));
});

const PORT = 3000;
server.listen(PORT, () => {
    console.log(`Server running at http://localhost:${PORT}`);
});

Run:

  node index.js
# or
npm start

Test with curl or browser:

  curl http://localhost:3000/users

ES Modules in Node.js

Add to package.json:

  {
  "type": "module"
}

Then use import/export:

  import http from 'http';

const server = http.createServer((req, res) => {
    res.end('Hello ES Modules!');
});

server.listen(3000);

Development Tips

  • Use node --watch index.js (Node 18+) for auto-restart on file changes
  • Install nodemon for older Node versions: npm install -D nodemon
  • Use VS Code with the Node.js extension for debugging