Node.js, Express.js & MongoDB Interview Cheat Sheet
Node.js, Express.js & MongoDB Interview Cheat Sheet Node.js (Basic) 1. What is Node.js? - Node.js is a runtime to run JavaScript on the server side. 2. What is the event loop? - A mechanism that handles asynchronous operations in Node.js. 3. What are callbacks? - Functions passed to other functions for asynchronous handling. Example: fs.readFile('file.txt', (err, data) => { if (err) return; console.log(data.toString()); }); 4. Difference between synchronous and asynchronous: - Sync blocks execution. Async uses callbacks/promises to avoid blocking. Express.js (Basic) 1. What is Express.js? - A lightweight web framework for Node.js. 2. Creating a basic server: const express = require('express'); const app = express(); app.get('/', (req, res) => res.send('Hello')); app.listen(3000); 3. What is middleware? - Functions executed during request processing. MongoDB (Basic) 1. What is MongoDB? - A NoSQL database using JSON-like documents. 2. Conne...
