JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li id="valid">#valid</li>
    <li id="0invalid">#0invalid</li>
</ul>

CSS

span{color:red}

JavaScript

$('li[id]').each(function()
{
    var check;
    try{
   document.querySelectorAll('#'+$(this).attr('id'));
        check='=&gt;valid ID'
   }catch(e){check='=&gt;<span>invalid ID(<i>'+e.message+'</i>)</span>'}
    $(this).append('<br/><b>'+check+'</b>');
}                 
);