33 Node JS Interview Questions and Answers to Ask Aspiring Node Developers

They are a part of the Technical Steering Committee , which services the consensus process on an ongoing basis. Developers who make important contributions become Collaborators and are granted commit access to the project. Speed – By using Google Chrome’s V8 JavaScript Engine, it enables fast code execution. One significant challenge that Node.js addresses is the inefficiency of OS threads. Let’s take a simple example using a “hello world” configuration written using Node.js as pictured below to see how this manifests.

Another difference is front-end development using AJAX and asynchronous requests. Front-end development relies on JavaScript, CSS, HTML, and similar web and markup languages. On the other hand, back-end development uses Ruby, Python, Perl, and other scripting and programming languages. Given that your response will rely on your prior knowledge of and exposure to programming, this is a challenging topic to answer. However, if you have any knowledge of JavaScript, we can claim that learning Node.js is not extremely challenging. Which of the following is/are true about the http.ServerResponse object in Node.js?

Node.js also owes some of its popularity to its JavaScript association. Since JavaScript is the most popular language, as evident from the Stack Overflow survey in 2020, many developers can start working on the Node.js library without steep learning. Now that we established what is Node, let’s dig into its architecture.

The npm and yarn both provide almost all libraries of JavaScript with extended features of controlling environment-specific configurations. We can use package.json junior node js developer and package-lock.json to maintain versions of libs being installed in a project. So, there is no issue in porting that app to a different environment.

Explain the difference between frontend and backend development?

It turns JavaScript code into machine code during execution by utilizing a JIT (Just-In-Time) compiler, as do many current JavaScript engines such as SpiderMonkey or Rhino . Use createServer function with a callback function using request and response as parameters. Mongoose – Mongoose is also a Node.js web application framework that makes it easy to connect an application to a database. ExpressJS – Express is a flexible Node.js web application framework that provides a wide set of features to develop web and mobile applications.

It’s a great help in developing both web pages and mobile apps. Stubs are certain functions that mimic the behavior of specific modules. They are most often used in test cases since they can provide the answers needed to solve some of the issues that might arise within the modules.

Why Do We Use NodeJs?

Screenshot of the official Node.js websiteOfficial packages are available on the website for all major platforms . Download and install the appropriate package for your system. Let’s see how you can create your first Node.js application. This section will show you how to run Node.js scripts from the command line. With Node.js, you can choose which version to run your server-side application on. As a result, you can use modern JavaScript features without worrying about any version-specific inconsistencies.

The entire file is split into chunks and then processed and sent back as a response one by one. After completing this step, they are finally removed from the buffer. Unlike the readFile process, the createReadStream process is effective for the processing of large files. In Node.js applications, modules are like JavaScript libraries and include a set of functions. To include a module in a Node.js application, we must use the require() function with the parentheses containing the module’s name. We can manage the packages in our Node.js project by using several package installers and their configuration file accordingly.

Question 6: What are ‘stubs’?

Node.js is an open-source, cross-platform JavaScript runtime environment used for executing JavaScript code outside of a web browser. My blog is for those who want to learn how to code in HTML, CSS, JavaScript, PHP and other languages. And also for those who need to learn a language quickly and from scratch. It is useful to know not only the syntax of the language, but also its history, practical possibilities and applications. All articles are written solely for the purpose of showing you how this or that mechanism works in web development languages. This is good news for front-end developers who work with JavaScript.

When you make a request to save something to the database, you know it’s going to take some time to write. This is the basics of JavaScript’s non-blocking computation model. Similarly, in Node JS, it can do the assign tasks and still keep listening to other events. When a user clicks or something has returned from the thread, it will do what’s needed to do.

Java Interview

They can create apps and websites using Node and make full use of all features. Intermediate developers are also familiar with ancillary frameworks and how to use them to facilitate development. As a result, your Node JS interview questions should be able to challenge the candidates’ intellect. Whenever an event gets fired, its listener function starts executing.

Node.js has multiple in-built events available through the events module and EventEmitter class which is used to bind events and event listeners. The Multi-Threaded Request/Response Stateless Model is not followed by the Node JS Platform, and it adheres to the Single-Threaded Event Loop Model. The Node JS Processing paradigm is heavily influenced by the JavaScript Event-based model and the JavaScript callback system. As a result, Node.js can easily manage more concurrent client requests. The event loop is the processing model’s beating heart in Node.js.

A single blog post like this is not enough to learn all there is to know about Node.js. The purpose of this article was to give you an overview of what Node.js is. As I mentioned earlier in the article, Node.js is open-sourced. It is actively maintained by developers from all over the world. Node.js allows you to write JavaScript on both client and server. Other developer participants can join in the efforts to support the larger Node.js community.

Event-driven​

Node.js operates on a single-thread, allowing it to handle thousands of simultaneous event loops. Here’s a diagram, provided by Sinform.com, that best illustrates https://xcritical.com/ Node.js architecture. As this particular request is simple and does not involve any complex operations, it does not require any separate thread to process it.

When using NodeJs with basic crud or HTML application there is no need for high hopes . Though NodeJs will make it more scalable, there is no need for expecting a traffic flood only because the application is powered by NodeJs. So when the data is provided straightforwardly by, by the server and specially where there is no need to have a separate API, in this case there is no need for using NodeJs. NPM is a popular Node.js package library and the jewel in the crown of the Node.js community. It has millions of downloadable libraries, organized according to specific requirements, and is the largest software registry in the world.

• The same applies to hiring Node.js developers, where interview questions are fundamental for assessing technical prowess.
• Additionally, developers can deploy an API to varied network conditions.
• It is passed as f‌irst parameter to the ‘request’ event.
• Similarly, in Node JS, it can do the assign tasks and still keep listening to other events.
• This is yet another one of the Node JS interview questions that do not directly relate to any of the Node functions in particular.
• You can ask questions we listed based on the level of your candidates and experience.

With the browser runtime, you can access the Document Object Model . Node.js uses a consensus-seeking model for its decision process. As each agenda item appears to reach consensus, a moderator asks if any of the collaborators object. If consensus still cannot be reached and as long as there are no additional objections, the agenda item goes to a “majority vote wins” system.

Consensus-Seeking Process

In Node.js, an EventEmitter is a class that includes all the objects capable of emitting events. This can be achieved by attaching named events that are emitted by the object using an eventEmitter.on() function. Thus whenever this object throws an event, the attached functions are invoked synchronously. On the other hand, the programmer errors are actual bugs in the application. Globally deployed packages cannot be imported using require() in Node application directly.

What is callback hell?

Examples might be simplified to improve reading and learning. Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content. While using W3Schools, you agree to have read and accepted our terms of use,cookie and privacy policy. “In a synchronous programming model, things happen one at a time” (Eloquent JavaScript, 2020, para. 4). Compared to that, in an Asynchronous model, multiple things can happen at the same time.

You can ask questions we listed based on the level of your candidates and experience. Make your screening process count to get the most promising candidates for the interview round. You can then use our interview questions to select your new Node developer. The interview round is a vital part of any recruitment process. Employers need to ask the right questions to candidates during the interview to screen for essential skills. The same applies to hiring Node.js developers, where interview questions are fundamental for assessing technical prowess.

Node.js Interview Questions and Answers For Experienced Professionals

Netflix, a global media service provider, uses Node.js, you may get the idea of how powerful this environment is. These are just a few reasons why some big brands, including Microsoft, are already using Node.js for their IOT development purposes. You can also read about some great features of Node.js in the next section. In Node.js, the concept of Punycode is used for converting one type of string into another type.