index.js
index.html
 
import React from 'react';
import ReactDOM from 'react-dom';
const myfirstelement = <h1>Hello React!</h1>
ReactDOM.render(myfirstelement, document.getElementById('root'));
/*
You are now watching a React file
through our 'Show React' tool.
Click the tab to check out
the 'index.html' file as well.
*/
 
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport"
      content="width=device-width, initial-scale=1" />
    <title>React App</title>
  </head>
  <body>
    <div id="root"></div>
  </body>
</html>