在做外贸商城系统开发或购物网站时，经常遇到一个功能，就是购物车，购物车一般使用Cookies插件辅助来实现，购物车里面有商品的id，数量，数量的增加总小，删除等功能。下面Google Speed 怎么用Cookie.js来实现一个购物增减等功能的小插件。
首页要引入JQuery.js 和 Jquery.cookie.js
https://cdn.bootcss.com/jquery-cookie/1.4.1/jquery.cookie.min.js
实现代码如下：
//购物车
var Cart = function () {
this.Count = 0;
this.Total = 0;
this.Items = new Array();
};
//购物车集合对象
var CartItem = function () {
this.Id = 0;
this.Name = "";
this.Count = 0;
this.Price = 0;
};
//购物车操作
var CartHelper = function () {
this.cookieName = "{$member_id}_repast_cart";
this.Clear = function () {
var cart = new Cart();
this.Save(cart);
return cart;
};
//向购物车添加
this.Add = function (id, name, count, price) {
var cart = this.Read();
var index = this.Find(id);
if(count==0){
this.Del(id);
}else{
//如果ID已存在，覆盖数量
if (index > -1) {
cart.Total -= (((cart.Items[index].Count * 100) * (cart.Items[index].Price * 100)) / 10000);
cart.Items[index].Count = count;
cart.Total += (((cart.Items[index].Count * 100) * (cart.Items[index].Price * 100)) / 10000);
} else {
var item = new CartItem();
item.Id = id;
item.Name = name;
item.Count = count;
item.Price = price;
cart.Items.push(item);
cart.Count++;
cart.Total += (((item.Count * 100) * (item.Price * 100)) / 10000);
// console.log(cart);
// cart.Total += (((cart.Items[index].Count * 100) * (cart.Items[index].Price * 100)) / 10000);
}
cart.Total=Math.round(cart.Total * 100) / 100;
this.Save(cart);
}
return cart;
};
//改变数量
this.Change = function (id, count) {
var cart = this.Read();
var index = this.Find(id);
cart.Items[index].Count = count;
this.Save(cart);
return cart;
};
//移出购物车
this.Del = function (id) {
var cart = this.Read();
var index = this.Find(id);
if (index > -1) {
var item = cart.Items[index];
cart.Count--;
cart.Total = cart.Total - (((item.Count * 100) * (item.Price * 100)) / 10000);
cart.Items.splice(index, 1);
this.Save(cart);
}
return cart;
};
//根据ID查找
this.Find = function (id) {
var cart = this.Read();
var index = -1;
for (var i = 0; i
