index
React Documentation
The easiest way to get started with React is to use this Hello World example code on CodePen. You don't need to install anything; you can just open it in another tab and follow along as we go through examples. If you'd rather use a local development environment, check out the Installation page.
The smallest React example looks like this:
ReactDOM.render(
<h1>Hello, world!</h1>,
document.getElementById('root')
); It renders a header saying "Hello World" on the page.
The next few sections will gradually introduce you to using React. We will examine the building blocks of React apps: elements and components. Once you master them, you can create complex apps from small reusable pieces.