Express.js Cheat Sheet for Beginners (Complete Backend Quick Guide)

If you're learning backend development with Node.js, then mastering Express.js is essential. I created this simple Express.js cheat sheet that developers can quickly use while building APIs or preparing for interviews. This guide covers the most important Express.js concepts in one place. What is Express.js? Express.js is a fast and minimal framework used to build: REST APIs Web applications Backend services Microservices It simplifies server creation and routing in Node.js. Basic Express Server Setup const express = require('express'); const app = express(); app.listen(3000, () => { console.log("Server running on port 3000"); }); This creates a simple server running on port 3000. Routing in Express.js Routing defines how your server responds to requests. app.get('/', (req, res) => { res.send("Hello World"); }); app.post('/user', (req, res) => { res.send("User created"); }); app.put('/user/:id', (req, res) => { res.send("User updated"); }); app.delete('/user/:id', (req, res) => { res.s