React Base Fiddle (JSX)

Starting point for creating JSFiddles with React.

HTML

<script src="https://unpkg.com/react@16/umd/react.development.js"></script>
<script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
<div id="container">
    <!-- This element's contents will be replaced with your component. -->
</div>

Babel + JSX

class Names {
  constructor (names) {
    this.names = names;
  }
  contains (names) {
    console.log(this);
	}
}

class Hello extends React.Component {
  constructor(props) {
  	super(props);
    
    this.namesInstance = new Names(["Madrid", "Paris"]);
  }
  
	handleClick = () => {
   this.namesInstance.contains(["Madrid"]);
  }
  
  render() {
    return <div onClick={this.handleClick}>Hello {this.props.name}</div>;
  }
}

ReactDOM.render(
  <Hello name="World" />,
  document.getElementById('container')
);