Most common Node.js interview questions

In this article, I will try to include some of the most common Node.js interview questions with their answers.

1. What is Node.js?
- Node.js is an open-source, cross-platform, server-side JavaScript runtime environment used for building scalable and high-performance network applications.

2. What is the difference between Node.js and JavaScript?
- Node.js is a runtime environment used to execute JavaScript code outside of a web browser, while JavaScript is a programming language used to create interactive and dynamic web pages and applications.

3. What is the purpose of the Node.js event loop?
- The Node.js event loop is a mechanism used to handle asynchronous and non-blocking I/O operations, allowing Node.js to handle large numbers of connections and requests without blocking the main thread.

4. What is the difference between callback functions and promises in Node.js?
- Callback functions are used in Node.js to handle asynchronous operations, while promises are a more modern and easier-to-use alternative that allow for cleaner and more readable code.

5. What is middleware in Node.js?
- Middleware in Node.js is a function or set of functions that are executed in the request-response cycle, allowing for additional functionality to be added to the application, such as authentication, logging, or error handling.

6. What is the purpose of the npm package manager in Node.js?
- The npm package manager is used in Node.js to manage and install packages and modules, allowing developers to easily reuse and share code.

7. What is the difference between the global and local scope in Node.js?
- The global scope in Node.js refers to variables and functions that are available throughout the entire application, while the local scope refers to variables and functions that are only available within a specific module or function.

8. What is the purpose of the require() function in Node.js?
- The require() function is used in Node.js to load and use modules, allowing developers to easily reuse and share code.

9. What is the purpose of the process object in Node.js?
- The process object in Node.js provides information about the current Node.js process, such as the environment variables, command-line arguments, and exit codes.

10. What is the purpose of the buffer object in Node.js?
- The buffer object in Node.js is used to represent and manipulate binary data, such as images, audio files, or network packets.

That’s all, now you have good knowledge about the most common Node.js questions being asked in interviews.

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