原生JS实现购物车功能

<div class="catbox">
    <table id="cartTable">
        <thead>
        <tr>
            <th><label>
                <input class="check-all check" type="checkbox">&nbsp;&nbsp;全选</label></th>
            <th>商品</th>
            <th>单价</th>
            <th>数量</th>
            <th>小计</th>
            <th>操作</th>
        </tr>
        </thead>
        <tbody>
        <tr class="on">
            <td class="checkbox"><input class="check-one check" type="checkbox"></td>
            <td class="goods"><img src="" alt=""><span>Casio/卡西欧 EX-TR350</span></td>
            <td class="price">5999.88</td>
            <td class="count"><span class="reduce"></span>
                <input class="count-input" type="text" value="1">
                <span class="add">+</span></td>
            <td class="subtotal">5999.88</td>
            <td class="operation"><span class="delete">删除</span></td>
        </tr>
        <tr class="on">
            <td class="checkbox"><input class="check-one check" type="checkbox"></td>
            <td class="goods"><img src="" alt=""><span>Canon/佳能 PowerShot SX50 HS</span></td>
            <td class="price">3888.50</td>
            <td class="count"><span class="reduce"></span>
                <input class="count-input" type="text" value="1">
                <span class="add">+</span></td>
            <td class="subtotal">3888.50</td>
            <td class="operation"><span class="delete">删除</span></td>
        </tr>
        <tr class="on">
            <td class="checkbox"><input class="check-one check" type="checkbox"></td>
            <td class="goods"><img src="" alt=""><span>Sony/索尼 DSC-WX300</span></td>
            <td class="price">1428.50</td>
            <td class="count"><span class="reduce"></span>
                <input class="count-input" type="text" value="1">
                <span class="add">+</span></td>
            <td class="subtotal">1428.50</td>
            <td class="operation"><span class="delete">删除</span></td>
        </tr>
        <tr class="on">
            <td class="checkbox"><input class="check-one check" type="checkbox"></td>
            <td class="goods"><img src="" alt=""><span>Fujifilm/富士 instax mini 25</span></td>
            <td class="price">640.60</td>
            <td class="count"><span class="reduce"></span>
                <input class="count-input" type="text" value="1">
                <span class="add">+</span></td>
            <td class="subtotal">640.60</td>
            <td class="operation"><span class="delete">删除</span></td>
        </tr>
        </tbody>
    </table>
    <div class="foot" id="foot">
        <label class="fl select-all"><input type="checkbox" class="check-all check">&nbsp;&nbsp;全选</label>
        <a class="fl delete" id="deleteAll" href="javascript:;">删除</a>
        <div class="fr closing" onclick="getTotal();">结 算</div>
        <input type="hidden" id="cartTotalPrice">
        <div class="fr total">合计：￥<span id="priceTotal">11957.48</span></div>
        <div class="fr selected" id="selected">已选商品<span id="selectedTotal">4</span>件<span class="arrow up">︽</span><span class="arrow down">︾</span></div>
        <div class="selected-view">
            <div id="selectedViewList" class="clearfix"><div><img src="http://www.jq22.com/demo/jquery-guc20151105/images/1.jpg"><span class="del" index="0">取消选择</span></div><div><img src="http://www.jq22.com/demo/jquery-guc20151105/images/2.jpg"><span class="del" index="1">取消选择</span></div><div><img src="http://www.jq22.com/demo/jquery-guc20151105/images/3.jpg"><span class="del" index="2">取消选择</span></div><div><img src="http://www.jq22.com/demo/jquery-guc20151105/images/4.jpg"><span class="del" index="3">取消选择</span></div></div>
            <span class="arrow">◆<span>◆</span></span> </div>
    </div>
</div>

<style type="text/css">
        *{margin:0;padding:0;list-style-type:none;}
        a{color:#666;text-decoration:none;}
        table{border-collapse:collapse;border-spacing:0;border:0;}
        body{color:#666;font:12px/180% Arial, Helvetica, sans-serif, "新宋体";}
        clearfix:after{content:".";display:block;height:0;clear:both;visibility:hidden}
        .clearfix{display:inline-table}
        *html .clearfix{height:1%}
        .clearfix{display:block}
        *+html .clearfix{min-height:1%}
        .fl{float:left;}
        .fr{float:right;}
        .catbox{width:940px;margin:100px auto;}
        .catbox table{text-align:center;width:100%;}
        .catbox table th,.catbox table td{border:1px solid #CADEFF;}
        .catbox table th{background:#e2f2ff;border-top:3px solid #a7cbff;height:30px;}
        .catbox table td{padding:10px;color:#444;}
        .catbox table tbody tr:hover{background:RGB(238,246,255);}
        .checkbox{width:60px;}
        .check-all{ vertical-align:middle;}
        .goods{width:300px;}
        .goods span{width:180px;margin-top:20px;text-align:left;float:left;}
        .goods img{width:100px;height:80px;margin-right:10px;float:left;}
        .price{width:130px;}
        .count{width:90px;}
        .count .add, .count input, .count .reduce{float:left;margin-right:-1px;position:relative;z-index:0;}
        .count .add, .count .reduce{height:23px;width:17px;border:1px solid #e5e5e5;background:#f0f0f0;text-align:center;line-height:23px;color:#444;}
        .count .add:hover, .count .reduce:hover{color:#f50;z-index:3;border-color:#f60;cursor:pointer;}
        .count input{width:50px;height:25px;line-height:15px;border:1px solid #aaa;color:#343434;text-align:center;padding:4px 0;background-color:#fff;z-index:2;}
        .subtotal{width:150px;color:red;font-weight:bold;}
        .operation span:hover,a:hover{cursor:pointer;color:red;text-decoration:underline;}

        .foot{margin-top:0px;color:#666;height:48px;border:1px solid #c8c8c8;border-top:0;background-color:#eaeaea;background-image:linear-gradient(RGB(241,241,241),RGB(226,226,226));position:relative;z-index:8;}
        .foot div, .foot a{line-height:48px;height:48px;}
        .foot .select-all{width:80px;height:48px;line-height:48px;color:#666;text-align:center;}
        .foot .delete{padding-left:10px;}
        .foot .closing{border-left:1px solid #c8c8c8;width:103px;text-align:center;color:#666;font-weight:bold;cursor:pointer;background-image:linear-gradient(RGB(241,241,241),RGB(226,226,226));}
        .foot .closing:hover{background-image:linear-gradient(RGB(226,226,226),RGB(241,241,241));color:#333;}
        .foot .total{margin:0 20px;cursor:pointer;}
        .foot  #priceTotal, .foot #selectedTotal{color:red;font-family:"Microsoft Yahei";font-weight:bold;}
        .foot .selected{cursor:pointer;}
        .foot .selected .arrow{position:relative;top:-3px;margin-left:3px;}
        .foot .selected .down{position:relative;top:3px;display:none;}
        .show .selected .down{display:inline;}
        .show .selected .up{display:none;}
        .foot .selected:hover .arrow{color:red;}
        .foot .selected-view{width:938px;border:1px solid #c8c8c8;position:absolute;height:auto;background:#ffffff;z-index:9;bottom:48px;left:-1px;display:none;}
        .show .selected-view{display:block;}
        .foot .selected-view div{height:auto;}
        .foot .selected-view .arrow{font-size:16px;line-height:100%;color:#c8c8c8;position:absolute;right:330px;bottom:-9px;}
        .foot .selected-view .arrow span{color:#ffffff;position:absolute;left:0px;bottom:1px;}

        #selectedViewList{padding:10px 20px 10px 20px;}
        #selectedViewList div{display:inline-block;position:relative;width:100px;height:80px;border:1px solid #ccc;margin:10px;float:left;}
        #selectedViewList div img{width:100px;height:80px;margin-right:10px;float:left;}
        #selectedViewList div span{display:none;color:#ffffff;font-size:12px;position:absolute;top:0px;right:0px;width:60px;height:18px;line-height:18px;text-align:center;background:#000;cursor:pointer;}
        #selectedViewList div:hover span{display:block;}
    </style>

<script>
    /**
     * Created by an www.jq22.com
     */
    window.onload = function () {
        if (!document.getElementsByClassName) {
            document.getElementsByClassName = function (cls) {
                var ret = [];
                var els = document.getElementsByTagName(‘*‘);
                for (var i = 0, len = els.length; i < len; i++) {

                    if (els[i].className.indexOf(cls + ‘ ‘) >=0 || els[i].className.indexOf(‘ ‘ + cls + ‘ ‘) >=0 || els[i].className.indexOf(‘ ‘ + cls) >=0) {
                        ret.push(els[i]);
                    }
                }
                return ret;
            }
        }

        var table = document.getElementById(‘cartTable‘); // 购物车表格
        var selectInputs = document.getElementsByClassName(‘check‘); // 所有勾选框
        var checkAllInputs = document.getElementsByClassName(‘check-all‘) // 全选框
        var tr = table.children[1].rows; //行
        var selectedTotal = document.getElementById(‘selectedTotal‘); //已选商品数目容器
        var priceTotal = document.getElementById(‘priceTotal‘); //总计
        var deleteAll = document.getElementById(‘deleteAll‘); // 删除全部按钮
        var selectedViewList = document.getElementById(‘selectedViewList‘); //浮层已选商品列表容器
        var selected = document.getElementById(‘selected‘); //已选商品
        var foot = document.getElementById(‘foot‘);

        // 更新总数和总价格，已选浮层
        function getTotal() {
            var seleted = 0;
            var price = 0;
            var HTMLstr = ‘‘;
            for (var i = 0, len = tr.length; i < len; i++) {
                if (tr[i].getElementsByTagName(‘input‘)[0].checked) {
                    tr[i].className = ‘on‘;
                    seleted += parseInt(tr[i].getElementsByTagName(‘input‘)[1].value);
                    price += parseFloat(tr[i].cells[4].innerHTML);
                    HTMLstr += ‘<div><img src="‘ + tr[i].getElementsByTagName(‘img‘)[0].src + ‘"><span class="del" index="‘ + i + ‘">取消选择</span></div>‘
                }
                else {
                    tr[i].className = ‘‘;
                }
            }
            selectedTotal.innerHTML = seleted;
            priceTotal.innerHTML = price.toFixed(2);
            selectedViewList.innerHTML = HTMLstr;

            if (seleted == 0) {
                foot.className = ‘foot‘;
            }
        }
        // 计算单行价格
        function getSubtotal(tr) {
            var cells = tr.cells;
            var price = cells[2]; //单价
            var subtotal = cells[4]; //小计td
            var countInput = tr.getElementsByTagName(‘input‘)[1]; //数目input
            var span = tr.getElementsByTagName(‘span‘)[1]; //-号
            //写入HTML
            subtotal.innerHTML = (parseInt(countInput.value) * parseFloat(price.innerHTML)).toFixed(2);
            //如果数目只有一个，把-号去掉
            if (countInput.value == 1) {
                span.innerHTML = ‘‘;
            }else{
                span.innerHTML = ‘-‘;
            }
        }

        // 点击选择框
        for(var i = 0; i < selectInputs.length; i++ ){
            selectInputs[i].onclick = function () {
                if (this.className.indexOf(‘check-all‘) >= 0) { //如果是全选，则吧所有的选择框选中
                    for (var j = 0; j < selectInputs.length; j++) {
                        selectInputs[j].checked = this.checked;
                    }
                }
                if (!this.checked) { //只要有一个未勾选，则取消全选框的选中状态
                    for (var i = 0; i < checkAllInputs.length; i++) {
                        checkAllInputs[i].checked = false;
                    }
                }
                getTotal();//选完更新总计
            }
        }

        // 显示已选商品弹层
        selected.onclick = function () {
            if (selectedTotal.innerHTML != 0) {
                foot.className = (foot.className == ‘foot‘ ? ‘foot show‘ : ‘foot‘);
            }
        }

        //已选商品弹层中的取消选择按钮
        selectedViewList.onclick = function (e) {
            var e = e || window.event;
            var el = e.srcElement;
            if (el.className==‘del‘) {
                var input =  tr[el.getAttribute(‘index‘)].getElementsByTagName(‘input‘)[0]
                input.checked = false;
                input.onclick();
            }
        }

        //为每行元素添加事件
        for (var i = 0; i < tr.length; i++) {
            //将点击事件绑定到tr元素
            tr[i].onclick = function (e) {
                var e = e || window.event;
                var el = e.target || e.srcElement; //通过事件对象的target属性获取触发元素
                var cls = el.className; //触发元素的class
                var countInout = this.getElementsByTagName(‘input‘)[1]; // 数目input
                var value = parseInt(countInout.value); //数目
                //通过判断触发元素的class确定用户点击了哪个元素
                switch (cls) {
                    case ‘add‘: //点击了加号
                        countInout.value = value + 1;
                        getSubtotal(this);
                        break;
                    case ‘reduce‘: //点击了减号
                        if (value > 1) {
                            countInout.value = value - 1;
                            getSubtotal(this);
                        }
                        break;
                    case ‘delete‘: //点击了删除
                        var conf = confirm(‘确定删除此商品吗？‘);
                        if (conf) {
                            this.parentNode.removeChild(this);
                        }
                        break;
                }
                getTotal();
            }
            // 给数目输入框绑定keyup事件
            tr[i].getElementsByTagName(‘input‘)[1].onkeyup = function () {
                var val = parseInt(this.value);
                if (isNaN(val) || val <= 0) {
                    val = 1;
                }
                if (this.value != val) {
                    this.value = val;
                }
                getSubtotal(this.parentNode.parentNode); //更新小计
                getTotal(); //更新总数
            }
        }
        // 点击全部删除
        deleteAll.onclick = function () {
            if (selectedTotal.innerHTML != 0) {
                var con = confirm(‘确定删除所选商品吗？‘); //弹出确认框
                if (con) {
                    for (var i = 0; i < tr.length; i++) {
                        // 如果被选中，就删除相应的行
                        if (tr[i].getElementsByTagName(‘input‘)[0].checked) {
                            tr[i].parentNode.removeChild(tr[i]); // 删除相应节点
                            i--; //回退下标位置
                        }
                    }
                }
            } else {
                alert(‘请选择商品！‘);
            }
            getTotal(); //更新总数
        }
        console.log("\u767e\u5ea6\u641c\u7d22\u3010\u7d20\u6750\u5bb6\u56ed\u3011\u4e0b\u8f7d\u66f4\u591aJS\u7279\u6548\u4ee3\u7801");
        // 默认全选
        checkAllInputs[0].checked = true;
        checkAllInputs[0].onclick();
    }
</script>