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">  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">  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>