题解 | #购物面板#

    let zhaji = 0;
    let kele = 0;
    let zongjia;

    var zhajiJian = document.getElementById('zjtaiduola');
    var zhajiJia = document.getElementById('zjtaishaola');
    var keleJian = document.getElementById('kltaiduola');
    var keleJia = document.getElementById('kltaishaola');

    var zjsl = document.getElementById('zjsl');
    var klsl = document.getElementById('klsl');
    var total = document.getElementById('total');

    zhajiJian.onclick = function () {
        if (zhaji > 0) {
            zhaji--;
            zongjia = (zhaji * 28) + (kele * 5);
            zjsl.innerText = zhaji;
            total.innerText = zongjia;
        }
    }

    zhajiJia.onclick = function () {
        zhaji++;
        zongjia = (zhaji * 28) + (kele * 5);
        zjsl.innerText = zhaji;
        total.innerText = zongjia;
    }

    keleJian.onclick = function() {
        if (kele > 0) {
            kele--;
            zongjia = (zhaji * 28) + (kele * 5);
            klsl.innerText = kele;
            total.innerText = zongjia;
        }
    }

    keleJia.onclick = function () {
        kele++;
        zongjia = (zhaji * 28) + (kele * 5);
        klsl.innerText = kele;
        total.innerText = zongjia;
    }