JSX and styling

JavaScript XML (JSX) is the syntax extension for JavaScript. It is not mandatory to use JSX with React, but there are some benefits that make development easier. For example, JSX prevents injection attacks because all values are escaped in JSX before they are rendered. The most useful feature is that you can embed JavaScript expressions in JSX by wrapping them with curly brackets; this technique will be used a lot in the following chapters. JSX is compiled into regular JavaScript by Babel.

In the following example, we can access a component’s props when using JSX:

function App(props) {
  return <h1>Hello World {props.user}</h1>;
}

Component props are covered in the next section.

You can also pass a JavaScript expression as props, as shown in the following code snippet:

<Hello count={2+2} />

You can use both inline and external styling with React JSX elements. Here are two examples of inline styling. This...