What is ReactJS and how it works

Amit Garg

Published 14 Feb, 2023

What is ReactJS?

React (also known as React.js or ReactJS) is a free and open-source front-end JavaScript library for building user interfaces and web applications based on components. It is maintained by Meta (formerly Facebook) and a community of individual developers and companies. The library first appeared in May 2013 and is now one of the most commonly used frontend libraries for web development.

React can be used as a base in the development of single-page, mobile, or server-rendered applications with frameworks like Next.js. However, React is only concerned with the user interface and rendering components to the DOM, so creating React applications usually requires the use of additional libraries for routing, as well as certain client-side functionality.  React offers various extensions for entire application architectural support, such as Flux and React Native, beyond mere UI.

Why is react so popular, you may wonder?

New technologies are always introduced as an innovative solution and an alternative to swapping the old ones. The original idea of application development has been completely revamped. It all began when Facebook introduced the JavaScript library into their newsfeed in 2011 and later Instagram in 2012. The purpose of the JavaScript library is to build interactive user interfaces as it lets build large web applications that change over time in a fast and reliable way, without reloading the page.

Well, the rich, multifaceted, and dynamically hyped, ReactJS is an open-source, trendiest, and component-based JavaScript library that is widely used to build reusable user interfaces components for web application.

React ensures efficiency, high code reusability and is a popular tool among developers. It is well known for its reusable components, virtual DOM, and unidirectional data flow, all of which make it a strong and adaptable tool for creating scalable and maintainable applications and that too faster, as compared to other frameworks or libraries. React libraries are growing at an enormous rate, helping developers in building rich efficient front-end abstractions by writing less code and in lesser time as well!

Here are some reasons why you might consider using React for your next project:

·        Easy to learn and use

React’s JSX syntax allows you to write HTML-like code in your JavaScript, which can make it easier to read and write.

·        Large Supportive Community

Due to its simplicity, performance, and flexibility, React has grown significantly in popularity and traction among developers since it was first created and made open-source by Facebook in 2013.Developers can easily learn and use React because the community offers a lot of resources, including tutorials, documentation, and sample code.

·        The era of Reusable Components: 

React components are typically small, self-contained units of code that manage their own state and behavior. Parent component passes information to child component via props. As a result, developers are able to create components that can be used again with various types of data and in various application components.

Additionally, React has a strong composition model that permits nesting of components inside of other components. This makes it simple to combine basic, reusable components to create complex user interfaces.

React components are a great way of using encapsulation. React component-based structure has proven its power not only for dynamic sites but also for content-based sites.

·        Easy debugging

React uses a virtual DOM (Document Object Model), a compact in-memory representation of the real DOM, which enables it to update the user interface (UI) quickly without having to re-render the entire page. This makes it easy to track down where an issue is occurring in the code and fix it quickly.

React also has a built-in developer tool called “React Developer Tools” that allows detailed information about the component’s state and props, allows developers to see the component hierarchy and since React has a strict unidirectional data flow it makes it easy to track the flow of data through the application identify and fix bugs.

·        Scalability and flexibility

React is scalable, which means it can be used to build large and complex applications. React is flexible and can be used in a variety of contexts, such as web, mobile, and desktop applications.

·        Fast rendering times

Async rendering – You can execute updates asynchronously with React’s async rendering capabilities

Incremental rendering – By rendering only the essential portions of the DOM, incremental rendering in React can enhance the performance of your application.

·        Better SEO

Search Engines hate heavy JavaScript pages because of reading troubles when the page is loaded in the browser. React has a pre-rendering feature that helps in getting an SEO friendly platform in both SPAs or multiple page applications that can be easily indexed by search engines since it can be rendered on the server side. This is made possible by the use of programs like React Router and React-Helmet, which let programmers manage the document header and create dynamic, client-side routing, respectively. Additionally, JavaScript can be executed by search engines, allowing it to be indexed even when it is rendered on the client side.

·        TypeScript support

React has built-in support for TypeScript, which can help you catch errors early and write more reliable code.

·        Cross-Platform Development

   React is a versatile technology that can be used to build applications for both web and mobile platforms. This makes it possible to write code once and use it across multiple platforms, which saves time and effort.

Popular apps built with react.js

Let us quickly discuss the React js application by looking at some of the most famous apps built with React js

·        Facebook

Presently, Facebook uses React js for supporting some of the app features. Their webpage is built with React, as the script that is blended in the application code. The mobile app is also built with a version of React called React Native which is similar, although responsible for displaying the iOS and Android native components instead of the DOM elements.

·        Instagram

Instagram is totally based on the utilization of ReactJS library and has let fans fully adapt to its amazing features. The use of ReactJS within Instagram is huge. A proof for that includes the geolocations, Google Maps APIs, search engine accuracy as well as tags that pop out without hashtags. It is all there in the API of the app – and is really impressive.

·        Netflix

The React version works with Netflix too – specifically on their platform called Gibbon which is used for low-performance TV devices instead of the DOM used in web browsers. Netflix has even publicly shared a blog post explaining how the ReactJS library helps its startup speed, runtime performance, modularity, and various other advantages.

·        Whatsapp

WhatsApp leverages ReactJS to create Facebook-based user interfaces alongside Underscore.js and Velocity.js.

Like the Facebook online experience discussed above, the all-new WhatsApp Web app has also been employing React as of late.

·        Discovery VR

Discovery VR is one of the top React Native virtual reality apps that allow exploring new characters, new places, and new ideas every day. The app was given the new opportunity as the technology has given an immersing experience never like before. Explore the globe with Discovery VR and watch incredible things on the go.

·        Dropbox

Dropbox has switched to ReactJS, when React became very popular amongst app developers. A plethora of resources are a part of this framework and are efficiently utilized by Dropbox as well – widely contributing to the success of this amazing cloud-based storage service and online backup solution.

·        Airbnb

     Airbnb incorporates React throughout its website to make the search function and communication easier.

 ·        Pinterest

Pinterest is a React app-based website that offers picture-sharing and social networking services to help people find new content and preserve it. Users have access to all material stored in their pinboards, whether it’s in the form of GIFs, photographs, or videos. All this is possible since the app is built with React.

 To wrap up..

Developed and maintained by Facebook, React has become one of the most sought-after technologies for front-end development. It’s growth since its inception has been phenomenal.

To sum up, React is a robust and adaptable JavaScript library with a variety of features and functionalities. It’s definitely a great tool for developing apps with bite-sized components that are easy-to-understand, virtual DOM, and unidirectional data flow, used for creating scalable and maintainable applications. Also finding solutions to frequent issues is made simple by its robust community, extensive ecosystem, and compatibility with other libraries.

You may have understood how React is helping developers write cleaner, lesser and more scalable code.