Node Js Online Test

1. What is the primary role of the passport module in Node.js authentication?

To create HTML templates To establish database connections To provide a middleware-based authentication framework for various strategies (e.g., local, OAuth) To handle routing

2. What does the "Callback Hell" or "Pyramid of Doom" refer to in Node.js?

A popular design pattern in Node.js A debugging tool A situation where nested callbacks result in unreadable and hard-to-maintain code A performance optimization technique

3. What is the WebSocket protocol identifier in a URL, often used for WebSocket connections in Node.js?

http:// ws:// tcp:// udp://

4. Which core module in Node.js is used to create web servers and handle HTTP requests and responses?

http fs net os

5. What is the primary trigger for AWS Lambda functions in serverless applications?

Database queries HTTP requests Manual execution Network monitoring

6. Which HTTP status code is typically returned in a Node.js RESTful API response to indicate a successful resource creation (POST request)?

200 (OK) 201 (Created) 204 (No Content) 400 (Bad Request)

7. What is the primary role of the crypto core module in Node.js?

To create HTML templates To manage database migrations To provide cryptographic functionality, such as encryption and decryption To define API routes

8. What is the role of process managers like PM2 when deploying a Node.js application to a production server?

To create HTML templates To handle database migrations To monitor and manage Node.js processes, ensure they stay running, and provide features like auto-restart To manage hardware devices

9. Which platform is Node.js built on top of?

.NET Java V8 JavaScript engine Ruby on Rails

10. What is a duplex stream in Node.js?

A stream that can only be read from A stream that can only be written to A stream that can be both read from and written to A stream that is used for network communication

11. What is Cross-Site Request Forgery (CSRF) in the context of web security, and how can it be mitigated in Node.js applications?

A technique for load balancing An attack where an authenticated user unknowingly performs actions on a different website A type of routing strategy An optimization technique

12. What is a common use case for npm scripts in a Node.js project?

Handling database connections Running unit tests, build processes, or application start scripts Defining routing for web applications Creating HTML templates

13. What is "request batching" in Node.js and how does it contribute to performance optimization?

A method for managing hardware devices Combining multiple HTTP requests into a single request to reduce overhead and improve efficiency A type of routing strategy A feature for handling database migrations

14. Which Node.js method is commonly used to schedule a function to run after a specified number of milliseconds?

setInterval setImmediate setTimeout process.nextTick

15. In Node.js, how is the connection to a PostgreSQL database typically established using the pg module?

By calling the pg.connect() method By specifying the database connection details in a JavaScript file By using the pg.createConnection() method and passing connection options By defining a new PostgreSQL class

16. In Express.js routing, how do you define a route parameter in a route URL pattern?

Using the param keyword By enclosing it in curly braces {} Using the req.param() method By adding a dollar sign $ before the parameter name

17. In Node.js, why is asynchronous programming important for handling I/O operations?

It makes I/O operations slower but more reliable. It prevents I/O operations altogether. It allows the program to continue executing other tasks while waiting for I/O operations to complete, avoiding blocking. It reduces the need for I/O operations.

18. What is middleware in Express.js?

A built-in JavaScript function A component used for database queries A function that handles specific tasks during the request-response cycle A package manager

19. What is the primary benefit of building serverless applications with AWS Lambda and Node.js?

Reduced scalability Simplified infrastructure management Increased hardware requirements Improved database performance

20. In Node.js, what is the purpose of using a secure connection (HTTPS) over HTTP for web communication?

To make the application slower To provide a more user-friendly experience To encrypt data transmission to protect against eavesdropping and man-in-the-middle attacks To improve database migrations