Javascript function return typeof number. But when typeof is omitted returns NaN
<p>I have a function that when the return statement is prefaced with <strong>typeof</strong> it says it's a number. But when I remove it it outputs <strong>NaN</strong>.</p>

<p>I don't understand why.</p>

<p>Here's a fiddle:</p>

<p><a href="http://jsfiddle.net/X3S56/" rel="nofollow">http://jsfiddle.net/X3S56/</a></p>

<p>Thank you.</p>
