Redefined undefined with a self-invoking function

fiddle.html

<p>First, undefined is defined to <em id="step1"></em></p>
<p>Then, undefined is redefined to <em id="step2"></em></p>

fiddle.js

$(document).ready(function() {
  undefined = false; // Undefined is defined to false
  $("#step1").text(undefined.toString());
  (function(undefined) { $("#step2").text(typeof undefined); })(); /* self-invoking function */
});

fiddle.manifest

name: Redefined undefined with a self-invoking function
authors:
  - dsimard from javascriptkata
normalize_css: no