What is "react"

Reactjs

React (sometimes called React.js or Reactjs) is an open-source Javascript library for creating user interfaces. It is maintained by Facebook, Instagram and a community of individual developers and other companies. According to the Javascript analysis service Libscore, React is being used on the websites of Netflix, Imgur, Feedly, Airbnb, Seatgeek, Hellosign, Walmart and others. [Wikipedia].

Simply the user interface

Many people use React as the V in MVC. React makes no assumptions about the rest of its technology stack and it’s easy to test it on a small resource in an existing project.

Virtual DOM

React uses a virtual DOM diff implementation for high performance. It can also render on the server using - no heavy browser DOM required. Also, there is a branch called to use React on mobile devices, such as and .

Data stream

React implements unidirectional reactive data flow using props that reduce Boilerplate and make it easier to understand than traditional bi-directional data binding.

Example using JSX

class HelloWorldComponent extends React.Component {
    render() {
        return (
            <div>
                Hello World!
            </div>
        );
    }
};

ReactDOM.render(
    <HelloWorldComponent />,
    document.body
);

List of major React component libraries