Node Js Online Test

1. What is asynchronous programming in Node.js?

A programming style that uses only synchronous functions A programming style that avoids using functions altogether A programming style that allows non-blocking execution of tasks, often involving callbacks or promises A programming style that focuses on single-threaded execution

2. What is "profiling" in the context of Node.js performance optimization, and how is it used?

A method for creating HTML templates A technique for monitoring and analyzing the behavior and performance of a Node.js application to identify bottlenecks and areas for improvement A type of routing strategy A way to handle HTTP requests

3. What is "auto-scaling" in the context of cloud-based Node.js applications, and how does it work?

Auto-scaling is the process of manually adding more servers to the cloud infrastructure. Auto-scaling is the automatic adjustment of server resources based on traffic and workload, typically achieved through cloud provider services like AWS Auto Scaling or Azure AutoScale. Auto-scaling is a load balancing technique. Auto-scaling is the process of optimizing database queries.

4. What is the purpose of breakpoints in a Node.js debugger?

To create HTML templates To pause code execution at a specific line or statement for inspection To optimize network connections To handle database migrations

5. What is middleware in the context of Node.js?

A database management system A software component responsible for managing hardware devices A function or set of functions that can be executed during the processing of HTTP requests in a web application A user interface framework

6. What is the primary goal of vertical scaling in Node.js application scalability?

To distribute requests across multiple servers To increase the processing power and capacity of a single server To optimize database queries To improve client-side performance

7. What is Node.js primarily used for?

Front-end development Back-end development Mobile app development Game development

8. In Node.js, what is the primary purpose of the "package.json" file?

To store application data To define the project's dependencies, scripts, and metadata To manage server configurations To execute JavaScript code

9. 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

10. What is the purpose of the WebSocket.on('message') event in Node.js WebSocket communication?

To log errors To close the WebSocket connection To handle incoming messages from the WebSocket clients To establish a secure connection

11. Which callback function is commonly used with the fs.readFile method to handle errors during file reading in Node.js?

onSuccess onComplete onFailure callback

12. In Node.js, which core module is used for working with file systems, including reading and writing files?

http fs net os

13. What HTTP methods are commonly used in RESTful APIs to perform CRUD (Create, Read, Update, Delete) operations on resources?

GET, POST, PUT, DELETE CREATE, FETCH, MODIFY, DELETE READ, WRITE, UPDATE, REMOVE REQUEST, RECEIVE, UPDATE, REMOVE

14. 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

15. In Node.js application scaling, what is a common use case for horizontal scaling?

Handling increased traffic and concurrent users Reducing server maintenance costs Improving code quality Implementing complex algorithms

16. Which core module is used for working with events and creating custom event emitters in Node.js?

http fs events url

17. What is a readable stream in Node.js?

A stream that can only be written to A stream that can only be read from A stream that can be both read from and written to A stream that is never used for I/O operations

18. In Express.js, how is middleware typically defined and used in the application pipeline?

Middleware is defined using the app.middleware method. Middleware is defined and applied using the app.use method, specifying the middleware function(s) as arguments. Middleware is defined in a separate configuration file. Middleware is automatically applied without any explicit configuration.

19. Which event is emitted by a readable stream when it reaches the end of the data?

data end readable finish

20. What is a "fixture" in Node.js testing?

A fixture is an external testing tool for load testing. A special keyword used in test case descriptions. A function or data setup that provides a known initial state for testing. A type of testing assertion.