Question

How can I set display:none to a ul if only has a single child?

This ul would be hidden, because it only has one li

<ul id="section">
  <li id="inThis">In this section:</li>
</ul> 

But this ul would not be hidden, because there are multiple lis

<ul id="section">
   <li id="inThis">In this section:</li>
   <li>Item 1</li>
   <li>Item 2</li>
</ul>

Answer 1

if($("#section li").length == 1)
{
   $("#section").hide();
}