Answer:
window.addEventListener("load", setupCart);
function setupCart() {
var addButtons = document.querySelectorAll("addButton");
for (var i = 0; i < addButtons.length; i++) {
addButtons[i].onclick = addItem();
}
}
function addItem(e) {
var foodItem = e.target.nextElementSibling;
var foodID = foodItem.getAttribute("id").value;
var foodDescription = foodItem.cloneNode(true);
var cartBox = document.getElementById("cart");
var duplicateOrder = false;
// Add duplicate items to cartBox
for (var i = 0; i < cartBox.childNodes.length; i++) {
if (cartBox.childNodes[i].id === foodID.id) {
cartBox.firstElementChild.value + 1;
duplicateOrder = true;
break; //stop processing the for loop
}
}
// Add new items to cartBox
if (!duplicateOrder) {
var orderCount = document.createElement("span");
orderCount.textContent = 1;
foodDescription.appendChild(orderCount);
cartBox.appendChild(foodDescription);
}
}
Explanation: