What is React JS and how does it work?

Jun 09, 2022

uses of react js

Without mobile and online applications, the world would not work in today’s world. From taxi bookings to meal orders to bank transactions, everything has gone digital. Because of well-designed frameworks that guarantee a pleasant user experience. One such powerful frontend library is React. This ‘what is React’ lecture will take you through the library’s basics and demonstrate how to utilize it with a simple demo.

What is React JS?

React is a UI development library based on JavaScript. It is run by Facebook and an open-source developer community. Despite the fact that React is more of a library than a language, it is frequently utilized in web development. The library debuted in May 2013 and has since grown to become one of the most widely used frontend libraries for web development.

Beyond only UI, React provides several extensions for full application architecture support, such as Flux and React Native.

Why React JS?

Today, React’s popularity has surpassed all other front-end development frameworks. This is why:

  • Easy creation of dynamic web apps: Compared to JavaScript, which can rapidly become challenging, React makes it easier to construct dynamic web applications by requiring less writing and delivering greater functionality.
  • Virtual DOM is used by React to speed up the development of internet projects. Virtual DOM checks the components’ former states and updates only the items in the Real DOM that have changed, rather than updating all of the components again as standard web applications do.
  • Components are the building blocks of every React application, and a single project often has many of them. These components have their own logic and controls, and they can be reused throughout the program, considerably decreasing development time.
  • React follows a unidirectional data flow. As a result, while creating a React project, developers commonly layer child components within parent components. Because data flows in a single conduit, debugging problems and pinpointing where a problem arises in an application at any given time becomes simple.
  • Because it combines essential HTML and JavaScript concepts with certain valuable additions, React has a low learning curve. You will, however, need to put in some effort to properly learn React’s library, just as you would with other technologies and frameworks.
  • It can be used to create both web and mobile applications: We already know that React is used to create web applications, but that’s not all it can accomplish. React Native is a popular framework that is derived from React itself and is used to create stunning mobile applications. React may therefore be used to create both web and mobile applications.
  • Debugging tools that are dedicated to the task: A Chrome extension for debugging React applications has been released by Facebook. Debugging React web applications becomes much faster and easier as a result of this.

The aforementioned arguments more than justify the React library’s success and adoption by a vast number of organizations and businesses. Let’s have a look at some of React’s features.

Features of React JS

React is a JavaScript package that makes it easier for developers to create user interfaces (UIs). In the context of websites and web applications, UIs are the collection of on-screen menus, search bars, buttons, and everything else that someone interacts with to USE a website or app.

Note: “Is React JS frontend or backend?” readers regularly ask. Without a doubt, the front end is the answer. You may recall the “on-screen” portion of UIs by remembering that React is a front-end library that is exclusively used for “client-side” programming (building things that a user will see on screen in their browser window).

Read more differences between frontend and backend 

Developers had to utilize “vanilla JavaScript” (development jargon for the raw JavaScript language) or less UI-focused React precursors like jQuery to create user interfaces before React JS. Defects and failures were more likely to occur with longer development cycles. As a result, Jordan Walke, a Facebook programmer, invented React JS in 2011 to help with UI development.

It comes with two essential features that contribute to its appeal to JavaScript developers: it provides reusable React library code (saving development time and lowering the likelihood of coding errors) and it comes with two essential features contribute to its appeal for JavaScript developers: it provides reusable React library code (saving development time and lowering the likelihood of coding errors) and it comes with two essential features that contribute to its appeal for JavaScript developers: it provides reusable React library code (saving development time and lowering the likelihood of (saving development time and reducing the chance of coding errors).

  • JSX
  • Virtual DOM


Every simple website relies on HTML pages to function. Web browsers read these documents and display them as web pages on your computer, tablet, or phone. During this process, browsers create a Document Object Model (DOM), which is a representational tree of how the web page is organised. Developers can then alter the DOM with languages like JavaScript to provide dynamic content to their applications.
JSX (JavaScript plugin) is a React extension that lets web developers change the DOM with simple HTML-style code. JSX is also compatible with any browser platform because React JS browser compatibility is accessible in all recent web browsers.

This isn’t simply for the sake of convenience; using JSX to update a DOM improves site performance and development efficiency significantly. How? It’s all about the Virtual DOM, the upcoming React feature.

Virtual DOM

If you don’t use React JS (and JSX), your website’s DOM (the process that allows objects to “change” on screen without requiring a user to actively refresh a page) will be updated using HTML. This is acceptable for simple, static websites, but it can be problematic for dynamic websites that require a lot of user involvement (since the entire DOM needs to reload every time the user clicks a feature calling for a page refresh).

React JS, on the other hand, creates a Virtual DOM when a developer uses JSX to control and update its DOM. The Virtual DOM is a duplicate of the site’s DOM, and React JS utilizes it to figure out which elements of the real DOM need to update when an event occurs (like a user clicking a button).

Consider a visitor who fills out a feedback form and hits the “Comment” button on a blog post. You’d have to update the entire DOM to reflect the change if you didn’t use React JS (using the time and processing power it takes to make this update). React, on the other hand, looks at the Virtual DOM to see what changed as a result of a user action (in this case, adding a remark) and only updates that part of the DOM.

This form of selective updating demands less computational power and loading time when it comes to a single blog comment, which may not seem like much, but when you consider all the dynamics and updating associated with even a fairly advanced website, it adds up rapidly.

How does React JS code appear?

If all of this makes sense, but you’re still stumped as to what React code is, keep reading. This React examples website will provide you with a visual representation of what React looks like. Each of the projects featured here provides an example of what can be done with React JS as well as a peek at the source code that was used to create it.

react js code

Meanwhile, if you’re still unsure about “what can be done with React JS,” keep reading. These easy projects curated by the official React website provide React JS templates to navigate through as you learn React JS. 

Finally, if you’re searching for a React JS tutorial to go with those React JS examples for beginners, ReactJS.org’s Intro to React is a React JS tutorial that requires no prior experience or knowledge. This is an excellent place to start whether you’ve already worked with the React library or you’re still finding out how to install React.

The landscape of React JS

React JS is frequently referred to as both a JavaScript library and a JavaScript framework, but which is it? Is it one or the other?

Our curriculum team at Greencube Solutions considers React JS to be a JavaScript library rather than a framework. This is a crucial distinction to make.

Hire a dedicated developer for your React JS project.

The distinction between JavaScript libraries (such as React) and JavaScript frameworks (such as Angular) is that with a library, the developer applies library code to individual instances that require it. Frameworks, on the other hand, offer a scaffolding that organizes your website or application and gives defined spaces for framework code to be inserted in.

To understand the difference between a library like React JS and a framework like Angular, consider code from a JavaScript library as furniture and decorations for a house you’ve previously built, and a framework is a model home template you use to construct the house.

Since its extensive ecosystem and extensibility make it such a versatile JavaScript library, React JS is sometimes mistaken for a full-fledged framework. When you use React JS to create UIs for websites and web applications, keep in mind that you have access to:

  • Components and bits of React code (building blocks of React code used to create specific parts of a user interface)
  • The ability to manipulate your DOM directly with JSX.
  • To boost the performance of your website, use a Virtual DOM.

Furthermore, React JS is an open-source project, which means that anyone can download and alter its source code for free. This also means that for any UI function you want to accomplish with React JS, there’s a React library for it. With React’s community-curated library add-ons, ranging from collections of specific UI features to whole React JS templates for constructing UIs from the ground up, your React library can grow tremendously.

Should you use React JS to develop your next project?

React may be the most popular JavaScript framework and library by the end of 2022, a position that doesn’t look to be threatened in the near future for the reasons mentioned above. However, whether Reactjs or React Native is the best choice for your next app or a strategic organizational decision for all apps, depends on a variety of criteria, both technical and business-related.

We’d love to hear from you if you need advice on which JS framework or library is ideal for your project’s technical requirements, or if you need to establish or scale your React resource by hiring a React JS developer or a dedicated React JS development team.

Based on a well-practiced in-house process, we can reliably price quote even huge, enterprise-level applications within 24 hours if you already have clear technical specifications. Alternatively, based on your overall feature requirements, we can assist you with finalizing detailed technical specs for a React application. For further information or to get a quote Contact us!

Tom Black
Miraj Mor

Miraj Mor is one of the young entrepreneur, leader and mind who invests a lot of time in the client relationship management and business development strategies. He is the backbone of the whole team.