The Ultimate Node.js Cheat Sheet for Developers

Welcome to the ultimate Node.js cheat sheet, your comprehensive guide to mastering Node.js, whether you're just starting out or looking to brush up on your knowledge. This post will cover installation, core modules, useful commands, and best practices for efficient Node.js development.

Getting Started with Node.js

Installing Node.js:
Download and install Node.js from nodejs.org. Choose the version recommended for most users, unless you have specific needs that require the latest features or earlier compatibility.

Verifying Installation:
Check that Node.js and npm (node package manager) were installed correctly by running:

node -v
npm -v

Key Node.js Commands

• Start a Node.js Application:

  node app.js

• Initialize a New Node.js Project:

  npm init -y

• Install a Package Locally:

  npm install package-name

• Install a Package Globally:

  npm install -g package-name

Important Node.js Modules

File System (fs)

• Read a file asynchronously:

  const fs = require('fs');
  fs.readFile('/path/to/file', 'utf8', (err, data) => {
    if (err) throw err;
    console.log(data);
  });

• Write to a file asynchronously:

  fs.writeFile('/path/to/file', 'Hello, world!', (err) => {
    if (err) throw err;
    console.log('File has been written!');
  });

HTTP

• Create an HTTP server:

  const http = require('http');
  const server = http.createServer((req, res) => {
    res.statusCode = 200;
    res.setHeader('Content-Type', 'text/plain');
    res.end('Hello World\n');
  });

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

Path

• Manage file paths:

  const path = require('path');
  console.log(path.resolve('app.js'));  // Resolves to absolute path

Debugging in Node.js

Basic Debugging:
Use console.log, console.error, and console.warn to output debugging information to the console.

Advanced Debugging:
Run Node.js in inspect mode and attach a debugger.

node --inspect-brk app.js

Environment Management

Setting Environment Variables:

export NODE_ENV=production

Accessing Environment Variables in Node.js:

console.log(process.env.NODE_ENV);

Working with npm

• Update a Package:

  npm update package-name

• List Installed Packages:

  npm list

• Uninstall a Package:

  npm uninstall package-name

Conclusion

This Node.js cheat sheet is designed to help you quickly find the command or code snippet you need to enhance your development workflow. Whether you're troubleshooting, setting up a new project, or learning the ropes, keep this guide handy to streamline your Node.js experience.

Stay curious and keep building amazing things with Node.js!