Question

Suppose I have this HTML structure:

<div id="Ancestor">
 <div>
   <div>
     ....
       <div class="DeepChild"></div>
...
<div id="NotAncestor">
 <div>
   <div>
     ....
       <div class="DeepChild"></div>

I want to know, when I click on a DeepChild div if it’s a descendant of Ancestor.

Something like this:

$('.DeepChild').click(function () {
   if (whichcondition?? === true) { IsFromAncestor = true; }
});

Answer 1

$(this).parents("#Ancestor").length > 0

If your parenthood class is static and doesn’t move over time, you may want to attach the listener only to the div who are nested in and ancestor:

$("#Ancestor .deepchild").click(...