Node js: Quiz, Questions, Mock Test

Node js: Quiz, Questions, Mock Test

Course Content

📌 Introduction to Node.js

🔹 What is Node.js?
✨ Key Features of Node.js
⚖️ Node.js vs PHP vs Python vs Java
🛠️ Node.js Architecture (Single-threaded, Non-blocking I/O)
📥 Installing Node.js & npm

node -v
npm -v

▶️ Running a Basic Node.js Script

node app.js

📌 Node.js Basics

🌍 Global Objects (__dirname, __filename, process, console)
📦 Modules in Node.js
🔗 Built-in Modules (fs, http, os, path, events)
🛠️ Creating Custom Modules
📤 Exporting & Importing Modules (module.exports, require)
♻️ Event Loop & Event-Driven Architecture
🔄 Callback Functions
⏳ Using setTimeout() & setInterval()
💾 Streams & Buffers

📌 File System (fs Module)

📖 Reading Files - fs.readFile
✍️ Writing Files - fs.writeFile
📌 Appending to Files - fs.appendFile
🗑️ Deleting Files - fs.unlink
📁 Creating & Deleting Directories - fs.mkdir, fs.rmdir
🔍 Checking File Existence - fs.existsSync

📌 HTTP Module & Web Server

🌐 Creating a Basic HTTP Server

const http = require("http");

const server = http.createServer((req, res) => {
  res.writeHead(200, { "Content-Type": "text/plain" });
  res.end("Hello, World!");
});

server.listen(3000, () => console.log("🚀 Server running on port 3000"));

🔄 Handling Requests & Responses
📍 Routing in HTTP Server
🗂️ Serving Static Files

📌 Node.js Packages & npm

📦 What is npm?
📥 Installing Packages - npm install
🗂️ Local vs Global Packages
📜 Package.json (dependencies, devDependencies)
🔢 Semantic Versioning (^, ~, *)
📌 Managing Scripts in package.json
🔄 Updating & Removing Packages

📌 Express.js Framework

⚡ What is Express.js?
📥 Installing Express

npm install express

🛠️ Creating an Express Server
🛑 Middleware in Express
🔀 Handling Routes (GET, POST, PUT, DELETE)
🗂️ Serving Static Files
🚨 Error Handling in Express
🛤️ Express Router

📌 Template Engines

📄 Using EJS (Embedded JavaScript Templates)
🎭 Using Handlebars (hbs)
🐶 Pug Template Engine

📌 Database Connectivity

🛢️ MongoDB with Mongoose

📥 Installing & Setting Up MongoDB
🔗 Connecting MongoDB with Mongoose
🗃️ Defining Mongoose Schemas & Models
🔄 CRUD Operations (Create, Read, Update, Delete)
📌 Querying & Filtering Data
✅ Mongoose Validation & Middleware

🛢️ MySQL with Node.js

📥 Installing MySQL Driver (mysql2)
🔗 Connecting to MySQL Database
🔄 Performing CRUD Operations
🗃️ Using Sequelize ORM

🛢️ PostgreSQL with Node.js

📥 Installing PostgreSQL Client (pg)
🔗 Connecting & Querying PostgreSQL
🗃️ Using Sequelize with PostgreSQL

📌 Authentication & Security

🔐 User Authentication (JWT, OAuth, bcrypt)
🛡️ Securing APIs (Helmet, CORS)
🔑 Password Hashing (bcrypt)
📊 Rate Limiting (express-rate-limit)
🔏 Environment Variables (dotenv)

📌 API Development with Node.js

🔧 Creating RESTful APIs
🔍 Handling Query Parameters & Route Parameters
🛑 Middleware (body-parser, morgan, cors)
🆕 API Versioning
📌 Implementing Pagination in APIs

📌 Working with WebSockets

🌐 Introduction to WebSockets
📡 Using ws Module for WebSockets
💬 Real-time Chat Application with WebSockets
🔗 WebSockets with Express & Socket.io

📌 Working with GraphQL

📊 Introduction to GraphQL
🛠️ Setting Up GraphQL Server
📌 Writing Queries & Mutations
🔄 Using Apollo Server with Node.js

📌 Node.js Testing

🧪 Unit Testing with Jest
🔍 Integration Testing with Mocha & Chai
🛠️ API Testing with Supertest
✅ Writing Test Cases for Express APIs

📌 Performance Optimization & Best Practices

⚡ Using cluster for Multi-threading
🔄 Load Balancing with PM2
📌 Using Caching (Redis, Memory-cache)
🔍 Debugging & Profiling with Node.js DevTools

📌 Deployment & Scaling

🚀 Deploying Node.js Apps on:
🌍 DigitalOcean
☁️ AWS (EC2, Lambda)
🔥 Firebase
⚡ Vercel & Netlify
🏗️ Heroku
🛠️ CI/CD with GitHub Actions
🐳 Using Docker with Node.js
☸️ Kubernetes & Containerization

📌 Sorting Example in Node.js

🔢 Sorting an Array of Numbers in Ascending Order


const numbers = [42, 5, 23, 16, 8, 15];


// Sorting in Ascending Order
const sortedNumbers = numbers.sort((a, b) => a - b);

console.log("📊 Sorted Numbers:", sortedNumbers);

✅ Explanation:
✔️ The numbers array contains unsorted numbers.
✔️ The .sort() method sorts them in ascending order.
✔️ The sorting function (a, b) => a - b ensures numerical sorting instead of lexicographical sorting.