react basic hello world

HTML

<div id="root"></div>

Scripts

<script src="https://unpkg.com/react/umd/react.development.js"></script>
<script src="https://unpkg.com/react-dom/umd/react-dom.development.js"></script>
<!--
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/18.0.0-alpha-5fa4d79b0-20211008/umd/react.production.min.js" integrity="sha512-5PVmWGoNJocWPdQJmJd1aRbz3cFcFgXctWKLWcitqtgX64jF+ttfg9g2oLltmeQ1HUo3gT6QchaMK3h+S+JG4Q==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
-->

Javascript

ReactDOM.render( /*#__PURE__*/
React.createElement("h1", null, "Hello, world!"),
document.getElementById('root'));