Node Js Online Test

1. What is the primary benefit of using middleware in a Node.js application?

It eliminates the need for routing. It simplifies the creation of HTML templates. It allows for modular and reusable code for tasks such as authentication, logging, and request processing. It improves the performance of database operations.

2. In Node.js, what is the "Poll" phase responsible for?

Executing timer callbacks Handling incoming network requests Cleaning up memory resources Blocking the event loop

3. What is the purpose of the console.log() statement in debugging Node.js code?

To create HTML templates To display output messages in the console for inspection To optimize database migrations To manage hardware devices

4. 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.

5. 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.

6. What is a WebSocket handshake in Node.js?

A process for establishing a secure connection using SSL/TLS A process where the client and server exchange encryption keys An initial HTTP request-response exchange to negotiate and establish a WebSocket connection A process for user authentication

7. 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

8. What does "REST" stand for in "RESTful APIs" in Node.js?

Robust Extensible Server Technologies Representational State Transfer Remote Endpoint Services for Transactions Reactive Event-driven Stateful Technology

9. What is "cold start" in the context of AWS Lambda and how can it affect serverless Node.js applications?

A type of AWS Lambda function that never executes The initial startup time for a Lambda function, which can cause latency for the first invocation A security feature of AWS Lambda An event source for Lambda functions

10. In a Promise, what does the "resolve" state indicate?

An error or rejection Successful completion of an asynchronous operation A pending state A failed state

11. In Node.js RESTful APIs, what is the purpose of the HTTP GET method?

To create a new resource To read or retrieve the representation of a resource To update an existing resource To delete a resource

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 a writable 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 never used for I/O operations

14. Which Docker command is used to build a Docker image from a Dockerfile for a Node.js application?

docker run docker start docker build docker create

15. Which JavaScript feature introduced in ES6 (ECMAScript 2015) is commonly used for handling asynchronous code in a more readable and maintainable way in Node.js?

Callbacks Promises Asynchronous functions Synchronous code

16. In Node.js RESTful APIs, what is the purpose of the HTTP PUT method?

To create a new resource To read or retrieve a resource To update an existing resource To delete a resource

17. In Node.js, which core module provides the foundation for working with streams?

http fs stream net

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

http fs net path

19. What is an advantage of using Yarn over npm for package management in Node.js projects?

Yarn provides a more extensive set of built-in modules. Yarn offers faster and more reliable dependency resolution and installation. Yarn is the official package manager for Node.js. Yarn has better support for browser-based applications.

20. When should error handling be implemented in Node.js code?

Error handling is optional and should be skipped for simplicity. Error handling should be implemented only for expected errors. Error handling should be implemented for all possible error scenarios to ensure robustness. Error handling is the responsibility of the operating system, not the developer.