JSFiddle - React, Tailwind, and code Playground

HTML

<div class="myclass">
<span class="foo">bar </span>
<span class="foo">bar </span>
<span class="foo">bar </span>
<span class="foo">bar </span>
<span class="foo">bar </span>
<span class="foo">bar </span>
<span class="foo">bar </span>
</div>

JavaScript

$(function(){

$(".myclass").on("DOMSubtreeModified", function(e){
 
		var collection = $(this).find('.foo');
		console.log(collection.length);
});


$('.foo').on('click', function(){ $(this).remove(); });
});