Node.js Documentation

Prerequisites

Node.js is a JavaScript runtime built on Chrome's V8 engine, designed for building fast and scalable network applications.

Install via the official installer or package manager:

# macOS with Homebrew
brew install node

# Windows installer from nodejs.org

Node.js uses CommonJS modules by default. Use require() or ES Modules with import/export:

// CommonJS
const fs = require('fs')

// ES Module
import fs from 'fs';

Manage packages with npm or pnpm:

npm init
npm install express --save

The event loop handles asynchronous operations. Use callbacks, promises, or async/await:

setTimeout(() => console.log('tick'), 1000);

async function read() {
  const data = await fs.promises.readFile('file.txt');
}

Interact with the file system using the fs module:

import { promises as fs } from 'fs';

async function save() {
  await fs.writeFile('data.json', JSON.stringify(obj));
}

Create HTTP servers:

import http from 'http';

http.createServer((req, res) => {
  res.end('Hello World');
}).listen(3000);