JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8" />
        <title>Hello React!</title>
        <script src="https://fb.me/react-0.14.2.js"></script>
        <script src="https://fb.me/react-dom-0.14.2.js"></script>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.23/browser.min.js"></script>
    </head>
    <body>
        <div id="example"></div>
        <script type="text/babel">
            "use strict"

            let a, b;

            function test(arg1 = 'test', arg2) {
                b = arg1; a = arg2;
            }

            let x   = ['Hello', 'World'].map(x => x.toUpperCase());
            const y = 'Webforumet';

            test(...x);

            [a, b] = [b, a];

            var o = { [a]: y, b: b };

            let arr = Object.keys(o).map(k => k === 'b' ? o[k] : k);

            ReactDOM.render(<div>{arr.join(' ')}</div>, document.getElementById('example'));

        </script>
    </body>
</html>