Node Js Online Test

1. Which Node.js function is used to add a callback to the "next tick queue" for execution in the next iteration of the event loop?

setTimeout setImmediate process.nextTick setInterval

2. In Node.js, what is the primary purpose of load balancing for performance optimization?

To slow down responses To manage hardware devices To distribute incoming traffic across multiple server instances to improve scalability and fault tolerance To create static HTML templates

3. What is the purpose of profiling in Node.js debugging tools?

To create HTML templates To analyze the performance of code and identify bottlenecks To manage hardware devices To simulate HTTP requests

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

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

5. What is an Object-Relational Mapping (ORM) library used for in Node.js and database connectivity?

To create static HTML templates To manage hardware devices To provide an abstraction layer that simplifies database operations by mapping database entities to JavaScript objects To establish network connections

6. In Node.js, which method is used to write data to a file asynchronously?

writeFile fs.write writeFileSync fs.writeFile

7. Which command is used to install Express.js in a Node.js project?

npm add express npm require express npm install express npm express create

8. What is the primary benefit of using a library like "inquirer.js" in Node.js CLI development?

It automatically generates HTML templates for CLI interfaces. It simplifies server-side rendering. It allows developers to create interactive and user-friendly command-line prompts and menus. It optimizes database queries.

9. What is a common technique for managing session data and maintaining user state in horizontally scaled Node.js applications?

URL rewriting IP whitelisting Sticky sessions or session affinity Content compression

10. Which core module allows Node.js applications to perform network operations and create network servers or clients?

http fs net path

11. Which Node.js module is commonly used for handling asynchronous operations and avoiding callback hell?

fs async http cluster

12. In an HTTP server created with Node.js, what is the primary purpose of a request handler function?

To manage the server's database To send audio files to clients To process incoming HTTP requests and generate appropriate responses To create HTML templates

13. In Node.js, which method is used to check if a file exists?

fs.exists fs.checkFile fs.access fs.fileExists

14. 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

15. In Express.js, what is the purpose of the app.all method when defining middleware?

To define a catch-all route for all HTTP methods To define middleware that can only be applied to GET requests To define middleware that is used for handling errors To define middleware for static file serving

16. 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.

17. What is the purpose of the ws module in Node.js?

To create HTML templates To establish database connections To provide a WebSocket server and client implementation To handle routing

18. 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)

19. What is the primary purpose of middleware in a Node.js application?

To manage database migrations To create HTML templates To process and manipulate HTTP requests and responses in a modular and organized manner To establish network connections

20. What is "SQL injection," and how can it be prevented in a Node.js application?

A method for optimizing database queries A type of routing strategy An attack where malicious SQL queries are injected into user inputs to manipulate the database A feature for handling HTTP requests