Misunderstood jQuery's "undefined" trick?
<p>jQuery uses this simple trick pattern : </p>

<pre><code>(function( $ , window,undefined ) {

alert(window.aaa===undefined); //true

}(jQuery,window))
</code></pre>

<p>But  , as far as I understand it was made because a foolish person might do this : </p>

<pre><code>undefined="lalala"
</code></pre>

<p>And then this should fail : </p>

<pre><code>(function( $ , window ) {

alert(window.aaa===undefined);

}(jQuery,window))
</code></pre>

<p><a href="http://jsbin.com/iculir/10/edit" rel="nofollow"><strong>but it doesn't</strong></a>. ( <em>it alerts true</em>)</p>

<p>What am I missing? </p>
