NODE.JS: Interview Questions

Have you ever found that technical interviews are a bit tricky? Well, the first reason why many people find coding interviews hard is that they lack the fundamental knowledge of the topic in question.

I have come up with some basic typical interview questions for Node.js, so let's get started!!

What is Node JS?

• Node.js is an open source server environment.
• Node.js is a platform built on Chrome's JavaScript runtime for easily building fast and scalable network applications.
• It is a single threaded, non-blocking and event driven.

When to use Node JS?

• Considering the main features of Node.js and its strengths, we can say data-driven, I/O-driven, event-driven, and non blocking applications benefit the best from a Node.js implementation.
• It can be used to create:

=> Web servers.
=> Real Time applications (chat applications, streaming, online games).
=> Command line applications.
=> Creating APIs.

As you just said Nodejs is a single threaded then how Nodejs is fast?

• Node js uses an event loop that handles the asynchronous tasks.
• The event loop makes our program non-blocking.
• We can handle multiple request at a time in parallel - that's the reason why node js fast.

Is it possible to access DOM in Node Js?

• No.

What is Express Js?

• Express is a node js web application framework that provides broad features for building web and mobile applications.
• It's a layer built on the top of the Node js that helps manage servers and routes.

What is Package.json file?

• The package.json file is the heart of any Node project.
• In package.json file we keep all the details of the projects that hold various metadata relevant to the project like version, description, dependencies, run scripts, license and all pm packages.
• Without this package, your project will not work.

What is Event Loop?

• The event loop makes the code async.
• Behind the scene when our code run asynchronously then there are containers that are:

=> call-stack,
=> call-back queue,
=> web API and
=> micro task queue.

• The purpose of event loop is to execute the async task as per priority.

That's it for now. Let me know what you think in the comments.