Create HTML string using Array.prototype.join
JavaScript
;(function () {
"use strict";
const listItems = ["firstItem", "secondItem", "thirdItem", "fourthItem", "fifthItem"];
const listItemsHTML = listItems.join("</li><li>");
const listHTML = `<ul><li>${listItemsHTML}</li></ul>`;
document.body.insertAdjacentHTML("afterbegin", listHTML);
})();