reactinaction.js

'use strict';
const e = React.createElement;
class FollowButton extends React.Component {
  constructor(props) {
    super(props);
    this.state = { follow: false };
  }
  render() {
    if (this.state.follow) {
        return 'You are following this.';
    }
  //create like button
    return e(
          'button',
          { onClick: () => this.setState({ follow: true }) },
          'Follow'
    );
  }
}
//get DOM entry point with an Id called root
const domEntryPoint= document.getElementById('root');
ReactDOM.render(e(FollowButton), domEntryPoint);