Backend Development with Nodejs Programming Quiz

1. What is a key feature of Node.js that allows it to handle multiple connections simultaneously?

• Synchronous processing
• Event-driven architecture
• Blocking I/O operations
• Multi-threading support

2. How can you create a RESTful API using Node.js?

• Use only callback functions without any error handling or routing.
• Write a synchronous function to serve data from a JSON file.
• Use Express.js to set up routes and handle HTTP requests.
• Create a new HTML page for every API endpoint manually.

3. What command is used to create a new Node.js project with npm?

• npm make
• npm create
• npm init
• npm start

4. What is the purpose of the `next()` function in Express middleware?

• The `next()` function sends a response to the client.
• The `next()` function passes control to the next middleware function.
• The `next()` function terminates the application.
• The `next()` function handles errors in middleware.

5. Which popular database can be easily integrated with Node.js?

• MongoDB
• PostgreSQL
• SQLite
• MySQL

6. What do you use to define routes in an Express application?

• res.send()
• req.body()
• app.get()
• next()

7. How do you serve static files using Express.js?

• Use the `static()` method to serve HTML files.
• Use the `file()` method to serve JSON files.
• Use the `express.static()` middleware to serve static files.
• Use the `send()` method to serve image files.

8. What is the role of the `package.json` file in a Node.js project?

• The `package.json` file executes server-side scripts directly.
• The `package.json` file stores all user data and preferences.
• The `package.json` file manages dependencies and scripts for a Node.js project.
• The `package.json` file contains only the project source code.

9. How can environment variables be accessed in Node.js?

• Using `config.environment()`
• Using `env.get()`
• Using `get.env()`
• Using `process.env`

10. What is the difference between `app.get()` and `app.post()` in Express?

• `app.put()` handles PUT requests while `app.post()` handles POST requests.
• `app.get()` handles GET requests while `app.post()` handles POST requests.
• `app.patch()` handles PATCH requests while `app.post()` handles POST requests.
• `app.delete()` handles DELETE requests while `app.post()` handles POST requests.

11. How can you handle CORS in a Node.js application?

• Use synchronous requests for API calls.
• Use the CORS middleware in Express.
• Disable security features in the browser.
• Set the Access-Control headers manually.

12. What is the purpose of the middleware function `body-parser` in Express?

• The `body-parser` middleware sends email notifications.
• The `body-parser` middleware logs request URLs.
• The `body-parser` middleware parses incoming request bodies.
• The `body-parser` middleware compresses response data.

13. Which command is used to install a specific version of a Node.js package?

• npm fetch package version
• npm get package@version
• npm add package version
• npm install package@version

14. How do you read a JSON file in a Node.js application?

• Use `fs.readFileSync()` and `JSON.parse()`.
• Use `require()` to read JSON files.
• Use `fs.writeFileSync()` to read JSON files.
• Use `JSON.load()` for reading files.

15. Which function is used to listen for connections on a specified port in a Node.js server?

• socket.bind()
• port.open()
• server.listen()
• connection.start()

16. What is the purpose of the `app.use()` method in Express?

• To define middleware functions that will process requests before they reach the route handlers.
• To send HTTP responses directly to the client.
• To establish database connections for the application.
• To generate HTML pages from templates.

17. How can you implement logging in a Node.js application?

• Create logging functions that block the event loop.
• Use a logging library like Winston or Bunyan.
• Write log messages directly to files manually.
• Use console.log for all logging needs.

18. What module is used for making HTTP requests from a Node.js application?

• UrlFetch
• Axios
• Fetch
• Request

19. How can you enable HTTPS in a Node.js application?

• Use the `http` module and set an environment variable.
• Use the `express` module to automatically enable HTTPS.
• Use the `fs` module to read SSL certificates.
• Use the `https` module to create a server with SSL certificates.

20. What does the `async` keyword do in Node.js?

• The `async` keyword defines a function that returns a promise.
• The `async` keyword blocks the event loop until the function is done.
• The `async` keyword allows synchronous functions to be defined.
• The `async` keyword pauses the execution until the function is complete.

21. How can you catch unhandled promise rejections in Node.js?

• Catch all errors with a `try-catch` block.
• Ignore them completely to avoid crashes.
• Use `setTimeout()` to delay the rejection.
• Use the `process.on(`unhandledRejection`, callback)` method.

22. What is the role of the `cookie-parser` middleware in Express applications?

• The `cookie-parser` middleware sends cookies to the client response object.
• The `cookie-parser` middleware is used to parse cookies attached to the client request object.
• The `cookie-parser` middleware encrypts cookies for security.
• The `cookie-parser` middleware handles session management in Express.

23. How do you validate incoming request data in an Express app?

• Validate using HTML5 attributes
• Use console.log for debugging
• Manual checks with if statements
• Use middleware like `express-validator`

24. What is the typical use case for using WebSockets with Node.js?

• Sending static files over HTTP
• Real-time communication in applications
• Compiling JavaScript on the client-side
• Making synchronous database queries

25. How do you create and use a custom middleware in Express?

• Middleware cannot be created in Express, it’s not supported.
• Middleware is created using `app.get(`/`, function(req, res) {…})`.
• You can create middleware by defining a function and using `app.use(function(req, res, next) {…})`.
• You create middleware by directly modifying the `req` and `res` objects only.

26. What do you need to do to deploy a Node.js application on a server?

• Store the app in a MySQL database.
• Use the command `npm start` to run your app.
• Upload the app files using FTP.
• Compile the application with Java.

27. How do you define and use environment-specific configurations in a Node.js app?

• Use a global config object for all settings.
• Hardcode configuration settings in application code.
• Use dotenv to manage environment variables.
• Create multiple config files for different environments.

28. What is the function of the `cors` package in a Node.js application?

• The `cors` package compresses HTTP responses.
• The `cors` package encrypts data in transit.
• The `cors` package manages database connections.
• The `cors` package enables Cross-Origin Resource Sharing.

29. Which module would you use to work with files and directories in Node.js?

• crypto
• url
• fs
• http

30. How can you terminate a running Node.js application gracefully?

• Kill the process using the `kill` command.
• Simply unplug the server.
• Use `process.exit()` to terminate the application gracefully.
• Force close the terminal window.