import carts from "./carts.js"
    const items = document.querySelectorAll('.carts-body .item')
    const total = document.querySelector('.total')
    const totalMoney = document.querySelector('.total-money')
    items.forEach((item, index)=> {
        item.querySelector('.id').textContent = carts.data[index].id
        item.querySelector('.name').textContent = carts.data[index].name
        item.querySelector('.unit').textContent = carts.data[index].unit
        item.querySelector('.price').textContent = carts.data[index].price
        item.querySelector('.num').value = carts.data[index].num
        item.querySelector('.money').textContent = carts.data[index].money
    })
    total.textContent = carts.total
    totalMoney.textContent = carts.totalMoney
    const prices = document.querySelectorAll('.carts-body .price')
    const nums = document.querySelectorAll('.carts-body .num')
    const monies = document.querySelectorAll('.carts-body .money')
    const checks = document.querySelectorAll('.carts-body .check')
    // forEach(在遍历的数组，数组的索引，数组)
    nums.forEach((num, index, arr)=>{
        num.onchange = ()=>{
            if(!checks[index].checked) return false
            monies[index].textContent = prices[index].textContent * num.value
            const numArr = [...arr].map((item)=> parseInt(item.value))
            total.textContent = numArr.reduce((pre, cur)=>pre + cur)
            const moneyArr = [...monies].map((item)=> parseFloat(item.textContent))
            totalMoney.textContent = moneyArr.reduce((pre, cur)=>pre + cur)
        }
    })
    const checkAll = document.querySelector('.check-all')
    let totalTmp = total.textContent
    let totalMoneyTmp = totalMoney.textContent
    checkAll.onchange = ()=>{
        checks.forEach((check)=>check.checked = checkAll.checked)
        if(checkAll.checked == false){
            let itemStatus = [...checks].every(item=>item.checked == false)
            if(itemStatus == true){
                total.textContent = 0
                totalMoney.textContent = 0
            }
        }else{
            total.textContent = totalTmp
            totalMoney.textContent = totalMoneyTmp
        }            
    }
    checks.forEach((check, index)=>{
        check.onchange = () =>{
            checkAll.checked = [...checks].every(item=>item.checked)
            if(check.checked == false){
                total.textContent -= nums[index].value
                totalMoney.textContent -= monies[index].textContent
            }else{
                total.textContent = total.textContent * 1 + nums[index].value * 1
                totalMoney.textContent = totalMoney.textContent * 1 + monies[index].textContent * 1
            }
        }
    })

总结：

把购物车项目js部分边看边写了一遍，把所有函数都变为箭头函数，简化代码，条理也很清楚；投票项目中把count赋值改为count = data[index]就可以把原始赋值带入；计划后续有时间自己再完全重写一遍购物车项目，包括CSS、html和js部分全部重写。

【文章原创作者：cc防御 http://www.558idc.com/gfip.html提供，感恩】