React Technology: Definition, Features, Uses, Examples. How To Create a React Web Application?

Anyone who is at least slightly interested in the web development world must have heard about React.js. It’s a powerful and popular front-end JavaScript library (not a framework!). React is used to create many everyday applications, including Netflix, Facebook, Instagram, Airbnb, and Dropbox.

What’s more, according to research by the State of JS, for a good couple of years, it has held a strong position among other technologies in terms of developers’ satisfaction, awareness, interest, and usage. And no wonder, since it lets entrepreneurs build custom web apps with beautiful interfaces and a remarkable User Experience. Compared to other technologies such as Angular.js, React brings excellent results when it comes to app performance and development speed, hence, development costs.

With that in mind, let’s dive into the story that will answer your React-related questions.

What Is React.js?

The React library was created by Facebook developers in response to an issue that its developers were facing. They were on the lookout for a way to build dynamic, interactive, and visually appealing interfaces with no loss in efficiency or performance. And that’s how React.js was born.

Originally intended for internal projects, it was launched as open-source in 2013 and has taken the JavaScript community by storm. It is still maintained by Facebook and now has millions of developers and hundreds of contributors.

How to Use React?

React.js is an efficient and elastic JavaScript library for building user interfaces. It allows engineers to quickly build complex UIs for web and mobile applications.

Its approach to building a user interface is component-based, meaning that a developer creates separate and isolated pieces of code with their own properties and functions, making the whole code easier to debug. This structure guarantees a number of business-friendly benefits, including better performance, faster development, and easier integration of new developers into projects, thanks to the clear code structure.

In addition to the React component structure, the uniqueness of React lies in two features: the usage of the JSX language and a Virtual DOM. Those who are interested in how it works will find a short, explanatory React.js dictionary at the end of this article.

App Development with React.js

As a JavaScript library, React.js is primarily used to build dynamic and responsive user interfaces for web applications. React’s principles can also be used for mobile application development through frameworks like React Native.

React Native allows developers to build truly native mobile apps for iOS and Android using their existing React knowledge. This is distinct from other cross-platform approaches like Ionic or Capacitor, which typically wrap a React web application in a web view. The flexibility of React.js makes it an ideal choice for building front-end user interfaces, especially those that require high user interaction.

Using this library, developers can build the app’s view model quickly and efficiently while keeping the code relatively simple. Apps built with this tool also deliver good performance, thanks to React’s virtual DOM.

React Key Features

The popularity and widespread adoption of this JavaScript library for front-end development can be attributed to its outstanding features, which include:

Component-Based Architecture

Components are considered the building blocks of any React application. They represent a part of the user interface, so instead of dealing with a monolithic or complex template, the entire user interface is broken down into smaller components, each with its own UI and code logic. This modular architecture makes it easier to manage intricate interfaces in React.

JSX

In React, JSX stands for JavaScript XML. It is a syntax extension for JavaScript that allows developers to write HTML-like code directly within their JavaScript files. This makes writing UI components more intuitive and readable.

Virtual DOM

React uses a Virtual Document Object Model to optimize performance. Unlike older approaches, where the entire DOM might be re-rendered for a small change, leading to slow applications, React creates a virtual copy of the DOM in memory. When data changes, React creates a new virtual DOM and compares it to the previous one. It then calculates the most efficient way to apply these changes to the real DOM, updating only the necessary parts. This results in faster rendering and a significantly smoother user experience

Unidirectional Data Flow

React enforces strict rules that ensure that data flows in only one direction, from parent components to child components or top to bottom. This unidirectional data flow makes it easier to understand the effect of data changes on UI components. This attribute makes it easy to debug React code.

Extension

More than just a user interface library, React has several extensions that cover the entire architecture of a full-fledged application. As a result, it can be used to build full-scale mobile apps. Tools like Flux and Redux can be used for state management, and frameworks like React Native can be used to extend React’s capabilities for building native mobile apps.

Benefits of React.js

React.js is a popular tool that developers can leverage to build dynamic user interfaces. Some of the reasons why it has become the go-to tool for developers are highlighted below.

Vibrant Open-Source Community

By choosing React.js, you get access to a massive global community of passionate developers who keep contributing to its growth. As one of the most popular open-source technologies, React benefits from a vast ecosystem of tools, libraries, and tutorials. The community still creates new frameworks and tools, such as Storybook and React Bootstrap, and provides support for anyone who is new to the React world. Plus, it has the giant of Meta standing behind it.

It Will Save You Time and Money

There are thousands of reusable components available as open-source libraries. Developers can put them in various project slots, working more efficiently instead of “reinventing the wheel.” This approach pushes much higher code quality while significantly decreasing the amount of time needed to build apps, therefore saving developers’ time and reducing project costs.

Better Performance

React was created to solve the issue of lousy performance in the context of more complex applications. Long story short, it worked. Thanks to the Virtual DOM, given its number of features and utility, it scores excellently when it comes to web performance, guaranteeing lightning-fast apps with low loading times.

Great UX and UI

React.js makes it easy to create dynamic web applications because it guarantees more functionality with less coding, which is a direct benefit of its component structure. The Virtual DOM offers a unique and effective way of updating an app’s views by only updating single components when changes are detected. This allows for the creation of advanced apps with interactive User Interfaces. The vast majority of components have been previously coded and placed in the GitHub repository.

One-Way Data Flow

In React.js, how a user sees a component depends on its state and props. A user’s actions, such as clicking on a button or filling up a field, can change a component’s internal state. When a component’s state or props change, React re-renders the component and its children, ensuring the UI stays in sync with the data. This approach makes the application more efficient, as the relationship between particular elements of the interface is clearly defined, less prone to errors, and easier to debug, as a developer has greater control over the data flow.

SEO-Friendly

While many traditional JavaScript frameworks struggled with search engine optimization, modern applications built with React can be highly SEO-friendly. By using techniques like Server-Side Rendering (SSR) or Static Site Generation (SSG) with frameworks like Next.js or Gatsby, React applications can deliver fully-rendered HTML to search engine crawlers. This improves indexing speed and reliability and can boost Core Web Vitals, a key factor in Google’s ranking algorithm.

Challenges in Using React.js

React.js remains a powerful JavaScript library. However, like any other technology, it does come with a number of unique challenges that developers have to navigate as they build with it. Some of these challenges are explained below.

State Complexity

Managing state, especially for complex apps, is one of the trickiest things about working with React. As an application grows, the interaction between the UI components can make it difficult to predict their behavior, leading to unexpected bugs. To solve this problem, consider using Redux, React Context, and other frameworks that can help you manage state more predictably. You can also modularize complex components. This will help localize complex state logic.

Over-fragmentation of Components

Although React uses a component-based architectural pattern, there’s a risk of overdoing it. This can lead to your project having multiple components that slow down performance and make it difficult to understand and navigate the codebase. As a general rule of thumb, any component that does not have reusable logic or is too small to justify its own file should be merged with other related interactive components.

Unnecessary Re-Renders Problem

Another problem with React components is that they have a tendency to re-render more often than necessary. This can affect their performance. To prevent unnecessary re-renders, consider using React.memo. You can also implement useCallback to wrap functions and values to ensure they’re preserved during re-renders.

Compatibility with Third-Party Libraries

React is a constantly evolving library. However, some of the third-party libraries used alongside this tool might not be able to keep up with the changes, leading to compatibility issues in the long run. Before integrating React with any third-party library, ensure that the external library is up to date with the current React version and that it is regularly maintained.

Performance Issues on Large Lists

React struggles with handling large lists or tables, and this causes performance lags. Libraries like React Window that can help virtualize React code can solve this problem. These tools render only visible items, reducing memory usage.

How to Build a React.js App?

There are two main options for building a React.js application. You can build an app from scratch using the React library and dependencies such as bundlers and a compiler. The alternative is to use a simpler approach by using a build tool like Create React App (CRA) or modern alternatives such as Vite, Astro, or Gatsby.

Building a React App from Scratch

To build with React from scratch, you need to manually install and configure all the dependencies that it needs to work. This includes installing React and React-DOM to get the core functionalities, a bundler to unify the different files, and a transpiler to make the code compatible with most browsers.

Webpack is one of the most popular module bundlers used to develop JavaScript applications. It packages JavaScript files and their dependencies into a single optimized bundle that can be used in web browsers.

For the compiler, you can install Babel, a popular JavaScript compiler used by developers to translate JavaScript code into a form that can seamlessly run on older browsers. With all of these installed, you can hop into building an application with React.

Building React Applications with a Framework

The official React team now recommends building new applications with a modern React framework. Frameworks like Next.js, Remix, Gatsby, and Astro provide a robust structure with features like routing, data fetching, and server-side rendering built in. These frameworks, often powered by fast-build tools like Vite, offer a much better developer experience and result in more performant applications.

Tools like Create React App (CRA), while historically popular, are no longer recommended for new projects as they lack the features of modern frameworks and are not actively maintained with the same velocity. For a simple client-side application, using a build tool like Vite directly is a more modern alternative to CRA.

Cross-platform development with React Native

React Native is a framework created by Facebook to speed up the process of mobile app development. Previously written React code allows you to build both Android and iOS apps simultaneously.

Historically, it used a “bridge” to translate JavaScript into native components. However, its new architecture, which uses a JavaScript Interface (JSI), allows for more direct communication between JavaScript and native code, resulting in significant performance improvements. Code, once written, can be used to build both iOS and Android native apps.

This is perfect if you need to build an uncomplicated mobile app without many resources. The more complex the app’s features are, the more native code snippets need to be written. The code created for scalable web applications may be reused for mobile ones, as developers can build a reusable library that can be leveraged in both web and mobile apps. This highlights the native vs cross platform development debate, where React Native offers a hybrid approach combining the benefits of both.

Is It Possible to Create a Server-Side Rendered App with React?

First, we need to clarify the main differences between client-side rendering and server-side rendering. In client-side rendering, a browser downloads a basic HTML web page, then renders the JavaScript parts and fills them with content.

Server-side rendering means the React components are rendered directly on the server, delivering HTML content. Combining it into a web application that can be rendered on multiple platforms simultaneously, we get an isomorphic application that renders on both the server and the client, or web browser, sides.

To create such an application, developers build a common React component tree, which is rendered on a server after the request. This results in sending HTML code with all the data to the browser, which later loads the JavaScript in the client version of a React application. There are two main advantages of such an approach:

• Improved SEO: While modern search engines like Google can process JavaScript, they do so more efficiently and reliably with pre-rendered HTML. SSR ensures that all content is immediately available to crawlers, which is beneficial for SEO.
• Better Perceived Performance: Users see meaningful content much faster because they don’t have to wait for a large JavaScript bundle to download and execute. This improves the user experience and key performance metrics like First Contentful Paint (FCP).

Use Cases of React in Web Development

React has proven its capabilities when building both Custom Web Applications, such as Netflix, Instagram, and PayPal, and simple single-page apps (SPAs). The main difference between a single-page application and a traditional multi-page app is that navigating an SPA does not require moving to an entirely new page.

Instead, views load within the same page. When proper routing is configured, single-page apps tend to be even faster and better optimized. Getting back to the types of apps you can build with React JS, there are a lot.

Social Networks

Social networks require dynamic, real-time interactions and seamless updates to keep users engaged and connected. React technology is well-suited for these platforms because it efficiently manages complex user interfaces and supports fast rendering of components, ensuring a smooth user experience even with frequent data changes.

Why Does It Work So Well?

• Great for building Single-Page Apps
• Easy social sharing with server-side rendering
• Simple real-time data processing with WebSockets

Examples:

• Pinterest
• Facebook
• Instagram

Video Platforms

​Video platforms require highly responsive and interactive user interfaces to provide seamless streaming experiences and real-time content updates. React technology is well-suited for this purpose as it efficiently manages complex UI components and ensures smooth rendering even during frequent data changes.

Why Does It Work So Well?

• Powerful single-page applications
• Good performance

Examples:

• Netflix

Sharing Economy Platforms

Sharing economy platforms rely heavily on dynamic, real-time interactions and seamless user experiences to connect service providers with consumers efficiently. React technology is particularly well-suited for these platforms because it enables fast rendering of interactive components and smooth updates without reloading the entire page.

Why Does It Work So Well?

• Great for building Single-Page Apps
• Easy social sharing with server-side rendering
• Simple real-time data processing with WebSockets

Examples:

• Airbnb
• Uber
• Uber Eats

SaaS Platforms

Software as a Service (SaaS) platforms demand highly dynamic, scalable, and responsive user interfaces to accommodate diverse user needs and frequent updates. React technology is particularly well-suited for SaaS development because it enables developers to build modular, maintainable, and fast-loading applications that enhance user productivity and engagement.

Why Does It Work So Well?

• Component reusability
• Quickly updated UI with Virtual DOM
• Quick rendering of pages with isomorphic JS

Examples:

• Asana
• InVision
• Zapier

E-commerce Platforms

React technology has become increasingly popular in the e-commerce sector due to its ability to create fast, scalable, and highly interactive user interfaces. It enables developers to build seamless user experiences that keep shoppers engaged and improve conversion rates.

Why Does It Work So Well?

• Easy component maintenance
• Great performance
• Interactive SPAs

Examples:

• Shopify
• Shopping.com

Communication Platforms

Communication platforms demand real-time responsiveness and seamless interaction to support dynamic conversations and instant updates. React technology excels in these environments by efficiently managing multiple interactive components and ensuring smooth rendering even under heavy user activity.

Why Does It Work So Well?

• Great for building Single-Page Apps
• Exquisite real-time data processing with WebSockets

Examples:

• WhatsApp
• Discord
• Skype

JSX Language

HTML files are the core of every basic website. They are read by web browsers and translated to appear on your devices as web pages with the desired UX and UI. To make it possible, browsers create a Document Object Model (DOM), a structure of how the particular components are arranged on the website.

Web developers may add dynamic content to web pages by adjusting the DOM with programming languages like JavaScript and additional extensions. JSX (JavaScript Extension) is a React extension for JavaScript that gives its users the opportunity to change the DOM with ready-to-use components written in simple, HTML-like code. It is known to save them a lot of time and significantly improve site performance. 

Virtual DOM in React.js

When not using JSX to modify the DOM, a website will probably go with HTML. And for basic, static websites, that is absolutely fine. However, things get tricky when you host a complex, dynamic website that requires a lot of user interaction. In that case, the entire DOM has to reload every time a user clicks on a button or fills in some fields on a form.

In a scenario where a developer uses JSX to update the DOM of their website, React.js creates the Virtual DOM (VDOM). It’s a virtual image of a UI that is saved in the memory and synchronized with the real DOM by a library, such as ReactDOM.

Using React’s declarative API, you can notify the DOM about which components need to be selectively refreshed and which ones should stay the same. This way, the page load speed improves, computer and internet memory usage decrease, and this results in a faster, more user-friendly site.

Interested in Using React Technology in Your Business? Contact CrustLab!

React.js is a powerful JS library that brings many benefits, such as component reusability, Virtual DOM, performance, stability, unidirectional data flows, and many others. Although it is not the perfect solution for every use case, it has helped many great businesses like Skype, Instagram, and Shopify build solid apps with great performance.

If you’re planning a software development project or following a web development checklist, React can be an excellent choice to consider. If you’re interested in using React for your business, feel free to contact us to learn more about this JavaScript library or to pick the right technology stack for your project!