JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://code.jquery.com/ui/1.9.0/jquery-ui.js"></script>

<div id="wrapper">
    <a href="#">link</a>
    <a href="#">link</a>
</div>
    
<div id="zero">
    <a href="#">link</a>
    <a href="#">link</a>
</div>

CSS

#zero {
 width: 0px;
 height: 0px    
}

JavaScript

document.write($("#wrapper").find(":focusable").size());
document.write("<br>");
document.write($("#zero").find(":focusable").size());