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

var arr = [0, 1, 2, 3];

class Hello extends React.Component {
  render() {
    return <div>
    	{arr.map(function(el) {
      	return el > 0 ? <div key={el}>number: {el}</div> : <div key={el}>number is too small</div>;
      })}
    </div>;
  }
}

ReactDOM.render(
  <Hello />,
  document.getElementById('container')
);