JSFiddle - React, Tailwind, and code Playground

HTML

<input type="button" value="Test" onclick="javascript:getElement()"/>

JavaScript

function getElement()
{
    var mydiv = document.getElementById("mydiv");
    
    if(!mydiv)
    {
        alert(typeof (mydiv));
    }
    mydiv = document.createElement("div");
    mydiv.style.width = 5+"px";
    mydiv.style.height = 5+"px";
    mydiv.id = "mydiv";
    document.body.appendChild(mydiv);
}