JSFiddle - React, Tailwind, and code Playground

HTML

<div id="div"></div>

JavaScript

$('<div></div>').attr('id', 'gen').appendTo($('#div'));

if($('#gen').length){
    alert("gen was found");
}
else{
   alert("gen was not found");
}

$('<div></div>').attr('id', 'gen2');


if($('#gen2').length){
    alert("gen2 was found");
}
else{
   alert("gen2 was not found");
}