Is there a shortcut syntax for checking types of variables?
<p>In JavaScript, how do I say:</p>

<pre><code>if (typeof obj === 'number' 
    || typeof obj === 'boolean' 
    ||  typeof obj === 'undefined' 
    || typeof obj === 'string') {
</code></pre>

<p>In other words, is there some kind of:</p>

<pre><code>if (typeof obj in('number','boolean','undefined','string')) {
</code></pre>
