cheat sheet

JavaScript

Node.js runtime, package managers, async patterns, array methods, and frontend tooling — a complete JavaScript reference for the command line and the browser.

#javascript#node#npm#cliupdated 04-26-2026

JavaScript

A practical reference for JavaScript in Node.js and the browser — from running your first script to configuring a production-grade toolchain.

What's in this section

TopicPages
Runtimeinstallation · node-runtime
Package managersnpm · npx · pnpm · yarn
Project configpackage-json · modules
Asyncasync-await · promises · fetch
Languagearray-methods · regex · errors
Toolingeslint · prettier · vitest · vite
  1. Installation — install Node.js via nvm or the official installer
  2. Node runtime — the REPL, running scripts, environment variables
  3. npm — the default package manager; understand it before the alternatives
  4. package.json — the heart of every JavaScript project
  5. modules — CommonJS vs ESM; when to use each
  6. async-await and promises — the async model
  7. fetch — HTTP requests in modern JS and Node
  8. array-methods — map, filter, reduce, and friends
  9. eslint + prettier — linting and formatting
  10. vitest + vite — testing and bundling

If you are working in TypeScript rather than plain JavaScript, start with the TypeScript section after completing the Node and npm pages here.