Node.js Interview Question and Answers

Node.js Interview Question and Answers

Node.js Interview Question and Answers: Node.js is an open-source, cross-platform runtime environment that allows developers to run JavaScript code outside of a web browser. Developed by Ryan Dahl in 2009, Node.js has gained immense popularity among developers due to its ability to handle asynchronous I/O operations and its event-driven architecture.

Node.js Interview Question and Answers: Node.js uses Google’s V8 JavaScript engine to execute code, making it a fast and efficient platform. It also has a rich library of modules, which makes it easy for developers to build web applications and scalable server-side solutions. Node.js is commonly used for building web servers, command-line tools, real-time chat applications, and many other types of software applications. Its popularity continues to grow, and it has become an essential tool for many developers around the world, Here we are Providing Important Node.js Interview Question and Answers.

Node.js Interview Question and Answers;

Question: 1. What is Node.js and how is it different from other JavaScript frameworks?

Answer: Node.js is an open-source, cross-platform runtime environment that allows developers to run JavaScript code outside of a web browser. It is different from other JavaScript frameworks in that it allows developers to build scalable server-side applications, while other frameworks are mainly focused on building client-side applications.

Question: 2. What is callback hell, and how can it be avoided in Node.js?

Answer: Callback hell is a situation in which nested callbacks make the code difficult to read and maintain. It can be avoided by using promises or async/await syntax, which make asynchronous code more readable and easier to manage.

Question: 3. What is the difference between process.nextTick() and setImmediate() in Node.js?

Answer: process.nextTick() executes the callback function immediately after the current function completes, but before the event loop continues. setImmediate() schedules the callback function to be executed in the next iteration of the event loop.

Question: 4. How does Node.js handle concurrency?

Answer: Node.js uses an event-driven, non-blocking I/O model to handle concurrency. This means that multiple requests can be handled simultaneously without blocking the event loop.

Question: 5. What is the difference between require() and import in Node.js?

Answer: require() is a synchronous function that loads modules into the current scope, while import is an asynchronous function that loads modules into a separate scope. Import is part of the ES6 module system, while require() is a part of the CommonJS module system.

Question: 6. What is middleware in Node.js and how is it used?

Answer: Middleware is a function that intercepts HTTP requests and responses in a Node.js application. It can be used to modify request/response headers, validate inputs, or add functionality to the application.

Question: 7. What is the purpose of the package.json file in a Node.js application?

Answer: The package.json file is used to store metadata about a Node.js application, including dependencies, scripts, and version information. It is also used by the npm package manager to install and manage packages

Question: 8. What is an event loop in Node.js?

Answer: The event loop is the core of Node.js. It is a loop that continuously monitors the event queue and processes events one by one. It keeps the application running by processing incoming events, such as HTTP requests, database queries, and I/O operations, in an asynchronous and non-blocking way.

Question: 9. What is npm in Node.js?

Answer: npm stands for Node Package Manager. It is the default package manager for Node.js, used for installing, updating, and managing packages or modules that are used in a Node.js project. npm provides a vast library of open-source modules and packages that can be easily installed and used in a Node.js application.

Question: 10. What are streams in Node.js?

Answer: Streams are used for handling data in a streaming manner, which means data is processed in chunks as it is received or sent, rather than waiting for the entire data to be available. Streams are used for handling large files, network protocols, and other I/O operations. Node.js provides four types of streams: Readable, Writable, Duplex, and Transform.

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