JSFiddle - React, Tailwind, and code Playground

by javascriptenlightenment

HTML

<script src="https://getfirebug.com/firebug-lite-debug.js"></script>
<!-- disregard this pane, html is shown in the "result" pane -->




































































<h4><strong>&larr; Code Example from <a href="http://www.javascriptenlightenment.com/" target="_blank">JavaScript Enlightenment Book</a> by <a href="http://www.codylindley.com" target="_blank">Cody Lindley</a></strong></h4>

<p>JavaScript code is executed on page load. Click the "Run" button in the top bar to re-run the JavaScript code. Output is logged to the <a href="http://getfirebug.com/firebuglite" target="_blank">Firebug Lite</a> console below &darr;.</p>

JavaScript

var initializedVariable; // declare variable

console.log(initializedVariable); // logs undefined
console.log(typeof initializedVariable); // confirm that JavaScript returns undefined

var foo = {};

console.log(foo.bar); // logs undefined, no bar property in foo object
console.log(typeof foo.bar); // confirm that JavaScript returns undefined