JSFiddle - React, Tailwind, and code Playground

HTML

<h1>hi</h1>

JavaScript

var test = [1, 2, 3, 4];

function addUl(arr) {
    var ul = document.createElement("ul");
    ul.setAttribute("id", "list");
    document.body.appendChild(ul);

    var li;
    var element;

    arr.forEach(function (a) {
        li = document.createElement("li");
        element = document.createTextNode(a);
        li.appendChild(element);
        document.getElementById("list").appendChild(li);
    });

}
addUl(test);