what is React.js?

The React.js framework is an open-source JavaScript framework and library developed by Facebook. It’s used for building interactive user interfaces and web applications quickly and efficiently with significantly less code than you would with vanilla JavaScript.

In React, you develop your applications by creating reusable components that you can think of as independent Lego blocks. These components are individual pieces of a final interface, which, when assembled, form the application’s entire user interface.

React’s primary role in an application is to handle the view layer of that application just like the V in a model-view-controller (MVC) pattern by providing the best and most efficient rendering execution. Rather than dealing with the whole user interface as a single unit, React.js encourages developers to separate these complex UIs into individual reusable components that form the building blocks of the whole UI. In doing so, the ReactJS framework combines the speed and efficiency of JavaScript with a more efficient method of manipulating the DOM to render web pages faster and create highly dynamic and responsive web applications.

What does React.js do?

Typically, you request a webpage by typing its URL into your web browser. Your browser then sends a request for that webpage, which your browser renders. If you click a link on that webpage to go to another page on the website, a new request is sent to the server to get that new page.

This back-and-forth loading pattern between your browser (the client) and the server continues for every new page or resource you try to access on a website. This typical approach to loading websites works just fine but consider a very data-driven website. 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, it requires manual DOM manipulation to reflect these changes. You must identify which data changed and update the DOM to reflect those changes, resulting in a full page reload.

How to Use React.js

In contrast to other frameworks like Angular, React doesn’t enforce strict rules for code conventions or file organization. This means developers and teams are free to set conventions that suit them best and implement React however they see fit. With React, you can use as much or as little as you need due to its flexibility.

Using React, you can create a single button, a few pieces of an interface, or your entire app’s user interface. You can gradually adopt and integrate it into an already existing application with a sprinkle of interactivity or, better yet, use it to build full-fledged powerful React applications from the ground up, depending on your need.