Test for empty jQuery selection result
<p>Say I do </p>

<pre><code>var s = $('#something');
</code></pre>

<p>and next I want to test if jQuery found #something, i.e. I want to test if <code>s</code> is empty.</p>

<p>I could use my trusty <code>isempty()</code> on it:</p>

<pre><code>function isempty(o) {
    for ( var i in o )
        return false;
    return true;
}
</code></pre>

<p>Or since jQuery objects are arrays, I suppose I could test <code>s.length</code>.</p>

<p>But neither seem quite in the idiom of jQuery, not very jQueryesque. What do you suggest?</p>
