A question about "undefined" in Javascript
<p>Today one of my friends said: </p>

<pre><code>if (typeof isoft == "undefined") var isoft = new Object();
</code></pre>

<p>is such kind of code is writted by a freshman and writes</p>

<pre><code>if(!isoft) var isoft = new Object();
</code></pre>

<p>I originally consider there must be some difference. But I can't find the difference. Is 
there any? Or are the two examples the same?</p>

<p>Thanks.</p>
