JavaScript如何从一个函数中获取目标值并乘以选中复选框的元素值
我的代码中有两个函数。第一个函数“addItem”在单击箭头增加/减少值时获取每个单独输入字段的值。第二个功能“复选框”验证的复选框是否已启用,如果已启用,则将预设数值添加到运行总数中。我很难弄清楚的是,只有在启用复选框并将其添加到我的总数时,如何获取输入字段值并将其乘以复选框值。同样,如果我将复选框切换为未选中状态,我将从总数中删除该值。现在,它所做的就是启用复选框,将复选框值添加到运行总数中,但在递增或递减时不考虑输入字段值。我希望它在用户更改输入值并启用复选框时动态计算总数。我希望我的解释有道理。我的代码如下。当然,我会在代码中添加一些额外的东西,但除非我让这个部分正常工作,否则我无法继续前进。感谢您的反馈,谢谢 index.htmlJavaScript如何从一个函数中获取目标值并乘以选中复选框的元素值,javascript,checkbox,user-input,getelementsbyclassname,Javascript,Checkbox,User Input,Getelementsbyclassname,我的代码中有两个函数。第一个函数“addItem”在单击箭头增加/减少值时获取每个单独输入字段的值。第二个功能“复选框”验证的复选框是否已启用,如果已启用,则将预设数值添加到运行总数中。我很难弄清楚的是,只有在启用复选框并将其添加到我的总数时,如何获取输入字段值并将其乘以复选框值。同样,如果我将复选框切换为未选中状态,我将从总数中删除该值。现在,它所做的就是启用复选框,将复选框值添加到运行总数中,但在递增或递减时不考虑输入字段值。我希望它在用户更改输入值并启用复选框时动态计算总数。我希望我的解释
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta class="viewport" content="width=device-width, initial-scale=1.0">
<link rel="stylesheet" type="text/css" href="style.css">
<title>Restaurant | Online Menu</title>
<link rel="shortcut icon" href="images/pngtree-green-leaf-icon-graphic-design-template-vector-png-image_3990501.jpg" type="image/x-icon" />
</head>
<div class= "nav-container">
<nav id= "nav-bar">
<a href= "index.html" class="active-link">Menu</a>
<a href= "about.html">About</a>
<a href= "Checkout.html">Checkout</a>
</nav>
</div>
<button id= "remove-button">Remove All</button>
<div id= "item-container">
<div class= "item-row">
<input type= "checkbox" class= "checkbox" value= "10"> Item#1 $10
<input class= "counter-Items" type= "number" placeholder= "How many?" min= "1" max="10" style="width: 100px"> <button class= "remove-button">Remove</button> <br><br>
</div>
<div class= "item-row">
<input type= "checkbox" class= "checkbox" value= "8"> Item#2 $8
<input class= "counter-Items" type= "number" placeholder= "How many?" min= "1" max="10" style="width: 100px"> <button class= "remove-button">Remove</button><br><br>
</div>
<div class= "item-row">
<input type= "checkbox" class= "checkbox" value= "6"> Item#3 $6
<input class= "counter-Items" type= "number" placeholder= "How many?" min= "1" max="10" style="width: 100px"> <button class= "remove-button">Remove</button><br><br>
</div>
<div class= "item-row">
<input type= "checkbox" class= "checkbox" value= "4"> Item#4 $4
<input class= "counter-Items" type= "number" placeholder= "How many?" min= "1" max="10" style="width: 100px"> <button class= "remove-button">Remove</button><br><br>
</div>
<div class= "item-row">
<input type= "checkbox" class= "checkbox" value= "2"> Item#5 $2
<input class= "counter-Items" type= "number" placeholder= "How many?" min= "1" max="10" style="width: 100px"> <button class= "remove-button">Remove</button><br><br>
</div>
<div id= "Total-Display">
<h3 id="display-total">Current Total $
<span id= "total-text"></span>
</h3>
</div>
<button id= "btn-checkout">Checkout</button>
<script src= "functions.js"></script>
<body>
<script src= "checkout-cart.js"></script>
</body>
</html>
餐厅|在线菜单
全部删除
项目#1 10美元
删除
项目#2$8
删除
项目#3$6
删除
项目#4$4
删除
项目#5$2
删除
当前总数$
结账
functions.js
const counterItems= document.getElementsByClassName('counter-Items')
const itemCheckBox = document.getElementsByClassName('checkbox')
const removeBtn= document.getElementById('remove-button')
const btnCheckout= document.getElementById('btn-checkout')
let total = JSON.parse(localStorage.getItem('myValue'))
document.getElementById('total-text').innerText = total
retrieveDOMElementsState()
btnCheckout.addEventListener('click', onClickBtnCheckout)
function onClickBtnCheckout () {
location.assign("/Checkout.html")
}
function retrieveDOMElementsState() {
let saveChkBxState= JSON.parse(localStorage.getItem('saveChkBxState')) || []
let inputFieldStoreValue= JSON.parse(localStorage.getItem('inputFieldStoreValue')) || []
Array.from(itemCheckBox).forEach((itemCheckBoxItem, aIndex)=> {
saveChkBxState.forEach((saveChkBxStateItem, bIndex) => {
saveChkBxStateItem===true && aIndex===bIndex ? itemCheckBoxItem.setAttribute('checked', true) : false
})
return retrieveDOMElementsState
})
Array.from(counterItems).forEach((counterItemsItems, aIndex)=>{
Array.from(inputFieldStoreValue).forEach((inputFieldStoreValueItem, bIndex)=>{
aIndex===bIndex ? counterItemsItems.value= inputFieldStoreValueItem : false
})
})
}
Array.from(counterItems).forEach(item=> {
item.addEventListener('change', onFieldChange)
})
Array.from(itemCheckBox).forEach(item=> {
item.addEventListener('change', onCheckBoxChange)
})
function onCheckBoxChange (e) {
let checkbox = e.target
let inputField = checkbox.nextElementSibling
let price = checkbox.value
let quantity = inputField.value
calcTotal(price, quantity, e.target.checked)
updateTotal()
}
function onFieldChange(e){
let saveChkBxState= Array.from(itemCheckBox).map(item=>{
return item.checked
})
localStorage.setItem('saveChkBxState', JSON.stringify(saveChkBxState))
let inputFieldStoreValue= Array.from(itemCheckBox).map(item=>{
return item.nextElementSibling.value
})
localStorage.setItem('inputFieldStoreValue', JSON.stringify(inputFieldStoreValue))
let inputField = e.target;
let checkbox = inputField.previousElementSibling;
let quantity = parseInt(inputField.value);
if(quantity < 0 || quantity > 10){
quantity = inputField.value = 0;
}
inputField.value = quantity;
if(checkbox.checked){
let price = checkbox.value;
let prevValue = inputField.prevValue;
calcTotal(price, prevValue, false);
calcTotal(price, quantity, true);
updateTotal();
}
inputField.prevValue = quantity;
}
function calcTotal(price, quantity, add=true){
price = price || 0;
quantity = quantity || 0;
if(add){
total+=(price*quantity);
}else{
total-=(price*quantity);
}
localStorage.setItem('myValue', JSON.stringify(total))
}
function updateTotal(){
document.getElementById('total-text').innerText = total;
}
removeBtn.addEventListener('click', onClickRemove)
function onClickRemove () {
localStorage.clear()
Array.from(itemCheckBox).forEach(item=>{
item.checked= false
})
Array.from(counterItems).forEach(item=>{
item.value= ''
})
total= 0
updateTotal();
}
const counterItems=document.getElementsByClassName('counter-Items'))
const itemCheckBox=document.getElementsByClassName('checkbox')
const removeBtn=document.getElementById('remove-button'))
const btnCheckout=document.getElementById('btn-checkout'))
让total=JSON.parse(localStorage.getItem('myValue'))
document.getElementById('total-text')。innerText=total
retrieveDOMElementsState()
addEventListener('click',onClickBtnCheckout)
函数onClickBtnCheckout(){
location.assign(“/Checkout.html”)
}
函数retrieveDOMElementsState(){
让saveChkBxState=JSON.parse(localStorage.getItem('saveChkBxState'))| |[]
让inputFieldStoreValue=JSON.parse(localStorage.getItem('inputFieldStoreValue'))| |[]
Array.from(itemCheckBox).forEach((itemCheckBoxItem,aIndex)=>{
saveChkBxState.forEach((savechkbxstateem,bIndex)=>{
saveChkBxStateItem===true&&aIndex==bIndex?itemCheckBoxItem.setAttribute('checked',true):false
})
返回检索到的元素状态
})
Array.from(counterties).forEach((countertitemsitems,aIndex)=>{
数组.from(inputFieldStoreValue).forEach((inputFieldStoreValueItem,bIndex)=>{
aIndex==bIndex?counterItemsItems.value=inputFieldStoreValueItem:false
})
})
}
Array.from(counterties).forEach(item=>{
item.addEventListener('change',onFieldChange)
})
Array.from(itemCheckBox).forEach(item=>{
item.addEventListener('change',onCheckBox更改)
})
函数onCheckBoxChange(e){
让复选框=e.target
让inputField=checkbox.nextElementSibling
让price=checkbox.value
让数量=inputField.value
calcTotal(价格、数量、e.target.勾选)
updateTotal()
}
功能更改(e){
让saveChkBxState=Array.from(itemCheckBox).map(item=>{
返回项目。已选中
})
setItem('saveChkBxState',JSON.stringify(saveChkBxState))
让inputFieldStoreValue=Array.from(itemCheckBox).map(item=>{
return item.nextElementSibling.value
})
localStorage.setItem('inputFieldStoreValue',JSON.stringify(inputFieldStoreValue))
让inputField=e.target;
复选框=inputField.previousElementSibling;
让数量=parseInt(inputField.value);
如果(数量<0 | |数量>10){
数量=输入字段。值=0;
}
inputField.value=数量;
如果(复选框。选中){
让价格=checkbox.value;
让prevValue=inputField.prevValue;
calcTotal(价格、价值、虚假);
calcTotal(价格、数量、真实值);
updateTotal();
}
inputField.prevValue=数量;
}
函数calcTotal(价格、数量、添加=真){
价格=价格| | 0;
数量=数量| | 0;
如果(添加){
合计+=(价格*数量);
}否则{
总计-=(价格*数量);
}
localStorage.setItem('myValue',JSON.stringify(总计))
}
函数updateTotal(){
document.getElementById('total-text')。innerText=total;
}
removeBtn.addEventListener('click',onClickRemove)
函数onClickRemove(){
localStorage.clear()
Array.from(itemCheckBox).forEach(item=>{
item.checked=false
})
Array.from(counterties).forEach(item=>{
item.value=“”
})
总数=0
updateTotal();
}
我对代码做了一些更改,使其按您的预期工作
const counterties=document.getElementsByClassName('counter-Items');
const itemCheckBox=document.getElementsByClassName('checkbox');
设total=0;
for(设i=0;i10){
数量=