Node.js Mastery Challenge

What is Express.js and why is it used in Node.js?

• Express.js is a database management system for Node.js.

• Express.js is a programming language used for mobile app development.

• Express.js is a web application framework for Node.js that simplifies server-side development.

• Express.js is a front-end framework for building user interfaces.

How do you create a simple Express server?

• 1. Install Express: npm install express; 2. Require Express: const express = require('express'); 3. Create app: const app = express(); 4. Define a route: app.get('/', (req, res) => res.send('Hello World!')); 5. Start server: app.listen(3000, () => console.log('Server running on port 3000'));

• Install Express globally with npm install -g express

• Run the server with python server.py

• Use Python Flask instead of Express

What middleware is commonly used in Express.js applications?

• body-parser, morgan, cors

• express-session

• passport

• helmet

How can you handle routes in Express.js?

• Handle routes using only middleware functions.

• Use app.route() for all HTTP methods.

• Define routes in a separate configuration file.

• Use app.get(), app.post(), app.put(), and app.delete() to handle routes in Express.js.

What is the purpose of the 'body-parser' middleware in Express?

• To manage database connections in Express.

• To serve static files in Express applications.

• To parse incoming request bodies in Express applications.

• To handle routing in Express applications.

How do you serve static files using Express.js?

• Use 'app.get(directoryPath)' to serve static files.

• Implement a middleware function to handle static files.

• Use 'app.use(express.static(directoryPath))' to serve static files.

• Set 'static: true' in the app configuration to serve static files.

What is the File System module in Node.js?

• The File System module in Node.js is a built-in module that allows for file and directory manipulation.

• The File System module is exclusively for database management.

• The File System module is used for network communication.

• The File System module is a third-party library for data visualization.

How do you read a file asynchronously using the File System module?

• Read the file using XMLHttpRequest.

• Use fs.readFileSync for synchronous reading.

• Utilize the readFile method from the HTTP module.

• Use fs.promises.readFile or fs.readFile with a callback.

What method would you use to write data to a file in Node.js?

• fs.appendFile

• fs.writeFile

• fs.createWriteStream

• fs.writeFileSync

How can you check if a file exists using the File System module?

• Use 'fs.isFile(filePath)' to determine if it exists.

• Use 'fs.existsSync(filePath)' for synchronous check or 'fs.access(filePath, fs.constants.F_OK, callback)' for asynchronous check.

• Use 'fs.fileExists(filePath)' to check existence.

• Call 'fs.checkFile(filePath)' for verification.