Node Js Online Test

1. 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.

2. What is a common use case for asynchronous programming in Node.js?

Real-time event handling Creating static HTML templates Processing large datasets Front-end design

3. In AWS Lambda, how can environment variables be set for Node.js functions?

They cannot be set; Lambda functions always use hard-coded values. Through the AWS Management Console, AWS CLI, or AWS SDKs By modifying the Lambda function code directly By creating a separate JSON configuration file

4. In Node.js, what is the purpose of the Event Loop in terms of performance optimization?

To create HTML templates To handle database migrations To manage hardware devices To efficiently manage I/O operations and callbacks

5. What type of applications are well-suited for Node.js development?

Scientific simulations Real-time applications, such as chat applications and online gaming 3D modeling and animation Batch processing applications

6. 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

7. 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.

8. What is "watch mode" in debugging tools like nodemon or ts-node-dev for Node.js?

A mode for executing code without any debugging A mode for monitoring code changes and automatically restarting the application during development A mode for profiling code performance A mode for handling HTTP requests

9. Which built-in Node.js module provides functions for working with file systems?

http fs net path

10. What is a "Docker image" in the context of containerization for Node.js applications?

A diagram representing the application's architecture A snapshot of the application and its dependencies, including the runtime environment A container management tool A code editor for JavaScript

11. 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.

12. What is the primary purpose of the os core module in Node.js?

To manage databases To create web servers To work with operating system-related information and utilities To handle HTTP requests

13. 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.

14. How can you run a script defined in the package.json file using npm?

By using the npm script command By executing the script directly with node By using the npm run command followed by the script's name By creating a separate shell script

15. In Node.js, what is the purpose of the "try...catch" statement in error handling?

To execute code repeatedly To handle asynchronous operations To catch and handle exceptions or errors that occur within a block of code To create HTML templates

16. 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

17. Which method is used to delete a file in Node.js?

fs.remove fs.deleteFile fs.unlink fs.delete

18. In Yarn, what is the purpose of the "yarn.lock" file?

To store application data To define project metadata and scripts To manage server configurations To lock down the specific versions of dependencies to ensure consistency

19. 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

20. 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