If you're starting out, I recommend you bootstrap your apps using npx create-react-app. It'll give you a good sense of what a React app could look like, and some pointers for file structure.
Most React apps have an index.html file, which you can use like any normal HTML file. But, for the majority of your app, it's recommended to write your content in JSX (otherwise, you aren't getting the benefits of using React in the first place).
JSX
JSX looks very similar to regular HTML, with a handful of key differences:
- Tag attributes tend to be in lowerCamelCase (
onChange rather than onchange)
- Instead of
class (which is a reserved keyword in JavaScript), you need to use className
An Example Component
I've borrowed this sample code from React's official tutorial, which you should definitely check out if you haven't already.
This is a class Component, and your JSX goes inside of the render method:
import React from 'react';
class ShoppingList extends React.Component {
render() {
return (
<div className="shopping-list">
<h1>Shopping List for {this.props.name}</h1>
<ul>
<li>Instagram</li>
<li>WhatsApp</li>
<li>Oculus</li>
</ul>
</div>
);
}
}
What goes in index.html?
The only essential part of index.html is a <div id="root"></div>, which React will use to append the rest of the JSX.
This is also the place to add the usual metadata and icons.
As an example, here's the index.html file that comes with create-react-app. For most of my projects, I leave this pretty-much as-is:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<meta name="theme-color" content="#000000" />
<meta
name="description"
content="Web site created using create-react-app"
/>
<link rel="apple-touch-icon" href="logo192.png" />
<!--
manifest.json provides metadata used when your web app is installed on a
user's mobile device or desktop. See https://developers.google.com/web/fundamentals/web-app-manifest/
-->
<link rel="manifest" href="%PUBLIC_URL%/manifest.json" />
<!--
Notice the use of %PUBLIC_URL% in the tags above.
It will be replaced with the URL of the `public` folder during the build.
Only files inside the `public` folder can be referenced from the HTML.
Unlike "/favicon.ico" or "favicon.ico", "%PUBLIC_URL%/favicon.ico" will
work correctly both with client-side routing and a non-root public URL.
Learn how to configure a non-root public URL by running `npm run build`.
-->
<title>React App</title>
</head>
<body>
<noscript>You need to enable JavaScript to run this app.</noscript>
<div id="root"></div>
<!--
This HTML file is a template.
If you open it directly in the browser, you will see an empty page.
You can add webfonts, meta tags, or analytics to this file.
The build step will place the bundled scripts into the <body> tag.
To begin the development, run `npm start` or `yarn start`.
To create a production bundle, use `npm run build` or `yarn build`.
-->
</body>
</html>
