ReactJS is a JavaScript library that builds reusable UI components declaratively, efficiently and flexible. It is an open-source, component-based front-end library that is responsible only for the application’s view layer. Originally developed and maintained by Facebook, it is now used in its products like WhatsApp and Instagram.
As internet and social media usage grew, web solutions became increasingly dependent on highly responsive user interfaces. The latest statistics show that 88% of users are unlikely to return to a website after a negative experience.
JavaScript frameworks are becoming more popular as more interactive apps are developed. Some of the most popular JavaScript frameworks are React, Angular, and Vue.
What is React.js?
React.js is a JavaScript library created by Facebook that simplifies the complex process of creating interactive user interfaces. React builds user interfaces as a collection of components that each output a small, reusable piece of HTML.
React is a framework for building applications by creating reusable components. Components such as these make up the application’s user interface when assembled together. The main purpose of React is to handle the view layer of an application, much like the V in a model-view-controller (MVC) pattern does, by providing the best and most efficient rendering implementation. React.js encourages developers to separate complex user interfaces into individual reusable components which form the building blocks of the whole interface, rather than dealing with it as a whole.
By doing so, ReactJS combines the speed and efficiency of JavaScript with a more efficient way to manipulate the DOM to render web pages faster and create highly dynamic and responsive web applications.
Why we use ReactJS?
ReactJS is used to develop User Interfaces (UI) that improve the speed of applications. It uses virtual DOM (JavaScript object), which improves performance. It is faster to use the JavaScript virtual DOM than the regular DOM. We can use ReactJS both client-side and server-side and with other frameworks. Component and data patterns help to improve readability and maintain larger applications.
What does React.js do?
You usually request a webpage by typing its URL into your web browser. It then sends a request for that webpage, which is then rendered by your browser. When you click on a link on that webpage, a new request is sent to the server for the new page.
When you access a new page or resource on a website, this back-and-forth loading pattern continues. Typically, this method of loading websites works just fine, but what if your website has a lot of data? The back and forth loading of the full webpage would be redundant and create a poor user experience.
Additionally, when data changes in a traditional JavaScript application, manual DOM manipulation is required. This will result in a full page reload, as you must identify which data changed and update the DOM to reflect those changes.
The React framework provides what is known as a single-page application (SPA). In a single-page application, only one HTML document is loaded on the first request. By using JavaScript, it updates the specific portion, content, or body of the webpage that needs updating.
When a user makes a new request, the client doesn’t have to reload the full webpage to get a new page. This pattern is known as client-side routing. By intercepting the request, React fetches and changes only the sections that need to be updated without having to reload the whole page. Using this approach results in better performance and a more dynamic user interface.
React uses a virtual DOM, which is a copy of the actual DOM. Whenever the data state changes, React’s virtual DOM is reloaded immediately to reflect this new information. React then compares the virtual DOM with the actual DOM to determine what has changed.
After finding the least expensive way to patch the actual DOM with that change, React finds the least expensive way to render the actual DOM.Therefore, React’s components and UIs reflect the changes very quickly since they don’t require reloading each time something changes.
How to Use React.js
React has fewer rules for code conventions and file organization than other frameworks like Angular. Therefore, developers and teams can set their own conventions and implement React however they prefer. You can use as much or as little React as you need because it is flexible.
Using React, you can create a single button, a few pieces of the interface, or the entire user interface of your app. Your application can be gradually adopted and integrated into the React ecosystem with a sprinkle of interactive features or you can build full-fledged applications from the ground up with React.
Features of React
Currently, ReactJS is gaining rapid popularity among web developers as the best JavaScript framework. It plays a crucial role in the front-end ecosystem. Here are some of the most important features of ReactJS.
- Performance
- Virtual DOM
- Simplicity
- JSX
- Components
- One-way Data Binding
History of React
A team of Facebook developers noticed that DOM was slow while developing a client-side application. A Document Object Model (DOM) describes HTML and XML documents using an application programming interface (API).
Document structure defines how documents are accessed and manipulated) React uses a virtual DOM which is a representation of DOM trees in JavaScript in order to make it faster. ReactJS is updated so frequently that it is quite difficult to navigate the version, which brings new features every time it is updated. Currently, the stable version of ReactJS is 18.2.0, released on June 14, 2022, and the first release was on May 29, 2013.
Final Thoughts
There is no doubt that React is one of the most popular JavaScript UI libraries in the world for creating modern applications. The powerful features and concepts that React introduced, such as JSX, virtual DOM, components, etc., make React stand out from other frameworks. At first, you don’t need to worry about libraries when learning React. Learn the basics, how React works, and what makes React different from other frameworks and libraries.
After creating a few barebones projects, you may feel the need to use some libraries. To get started, pick a library that has great documentation so you can solve most problems. In comparison to other libraries, such as Angular and Vue, React has a large community. For those who are interested in learning React, the job market is looking good, and many positions are available.
Learning React isn’t easy, but it pays off in the end. It is a technology that opens doors for those who learn it and helps them become better developers.