JSFiddle - React, Tailwind, and code Playground

HTML

<div id="demo">hi</div>

JavaScript

function myFunction() {
    var hege = [34, 12];
    var stale = [1, 78, 8, 4];
    var children = hege.concat(stale).sort(); 
    document.getElementById("demo").innerHTML = children;
}
myFunction();