我的购物车有效（运行总计），直到我移除某个项目，然后该总计读取了我移除该项目之前的最后一个总计，这肯定是某个地方的拼写错误，但是我已经看了3天了，现在有什么帮助吗？错误消息：cart.js：154未捕获的TypeError：无法读取未定义的属性'innerText'在HTMLButtonElement.removeCartItem（cart.js：52）的updateCartTotal（cart.js：154）处对于明天到期的学校项目，我正在简化网络开发，但是我显然迷失了方向。
if(document.readyState == "loading") { document.addEventListener("DOMContentLoaded", ready) } else { ready() } function ready () { //get the btn-danger class as a variable var removeCartItemButtons = document.getElementsByClassName("btn-danger") //loop through the buttons waiting for them to be clicked and then perform the function to remove them from the cart for (var i = 0; i < removeCartItemButtons.length; i++) { var button = removeCartItemButtons[i] button.addEventListener("click", removeCartItem) } //fix quantity updating the total and stopping negative cart quantities var quantityInputs = document.getElementsByClassName("cart-quantity-input") //loop throught the quantities listening for when the input changes its value for (var i = 0; i < quantityInputs.length; i++) { //input = whatever iteration we are on var input = quantityInputs[i] //listen for a change and execute function "quantityChanged" input.addEventListener("change", quantityChanged) } //creating the javascript for all add to cart buttons on the site var addToCartButtons = document.getElementsByClassName("shop-item-button") //constantly looping throught the buttons waiting for an event for (var i = 0; i < addToCartButtons.length; i++) { //whatever button is clicked executes the function var button = addToCartButtons[i] button.addEventListener("click", addToCartClicked) } } function removeCartItem(event) { //on the function event the target of the event is to remove boththe element its inside and also the element that that element is inside... the double parentElement var buttonClicked = event.target buttonClicked.parentElement.parentElement.remove() //call the function that updates the total price updateCartTotal () } //this function is what we want to do when the quantity value is changed function quantityChanged(event) { //get the quantity in the input var input = event.target //check if theres a number in the input and that it is at least 1 if (isNaN(input.value) || input.value <= 0) { input.value = 1 } //once we no theres is a valid number entered, call the function to update the cart again updateCartTotal() } //the function executed when add to cart buttons are clicked function addToCartClicked(event) { //initialises the button as the event target var button = event.target //getting the parent div the button is in var shopItem = button.parentElement //getting the div where the details of the product is var title = shopItem.getElementsByClassName("details")[0].innerText //the price of the product var price = shopItem.getElementsByClassName("price")[0].innerText //and the src of the product var imageSrc = shopItem.getElementsByClassName("shop-item-image")[0].src console.log(title,price, imageSrc) addItemToCart(title, price, imageSrc) updateCartTotal() } //creating a new method for adding all this into the cart keeping the title price and imageSource variables with the function function addItemToCart(title, price, imageSrc) { //creating an empty div var cartRow = document.createElement("div") cartRow.classList.add("cart-row") //adding the newly created cart row to the cart items var cartItems = document.getElementsByClassName("cart-items")[0] //stop duplicate items in the cart //get the names of all the items var cartItemNames = cartItems.getElementsByClassName("cart-item-title") //loop through the names for (var i = 0; i < cartItemNames.length; i++) { //check if the names in the cart equal to the title I am adding if(cartItemNames[i].innerText == title) { //alert that the item is already in the cart alert("this item is already in your cart") return } } //show what to put into the rows and replace the image, title and price on each new item var cartRowContents = ` <div class="cart-row"> <div class="cart-item cart-column"> <img class="cart-item-image"src="${imageSrc}" width="100" height="100"> <span class="cart-item-title">${title}</span> </div> <span class="cart-price cart-column">${price}</span> <div class="cart-quantity cart-column"> <input class="cart-quantity-input" type="number" value="1"> <button class="btn btn-danger">Remove</button> </div>` cartRow.innerHTML = cartRowContents //add the items onto the cart cartItems.append(cartRow) //event listener for the remove button cartRow.getElementsByClassName("btn-danger")[0].addEventListener("click", removeCartItem) //event listener for quantity changed cartRow.getElementsByClassName("cart-quantity-input")[0].addEventListener("change", quantityChanged) } function updateCartTotal () { //get the first cart items element var cartItemContainer = document.getElementsByClassName("cart-items")[0] //get the cart rows but only from the cart items var cartRows = cartItemContainer.getElementsByClassName("cart-row") //initialise the total var total = 0 //loop through the cart rows for price and quantity for (var i = 0; i < cartRows.length; i++) { var cartRow = cartRows[i] //get the first pricee var priceElement = cartRow.getElementsByClassName("cart-price")[0] //get the quantity var quantityElement = cartRow.getElementsByClassName("cart-quantity-input")[0] //Get the information from inside the element not just the element itself, replace the euro sign with nothing and make it a Number var price = parseFloat(priceElement.innerText.replace("€", "")) //get the quantity and multiply it by the price for the running total var quantity = quantityElement.value total = total + (price * quantity) } //multiplying the totoal by 100 and divinding by 100 again will round the total to stop any .999999999998's showing up total = Math.round(total * 100) / 100 //update the total price add the euro sign back in document.getElementsByClassName("cart-total-price")[0].innerText = "€" + total }感谢能帮助我的人
我的购物车一直有效（正在运行），直到我删除一个项目，然后总计读取了我删除该项目之前的最后一个总数，这肯定是某个地方的拼写错误，但是我一直在查看它3个...
cart-price元素中没有类别为cart-row的元素。