优化这段代码 let useGoodsList = [] goodsList.forEach(i => { if (item.goodsId.includes(i.id) || !item.goodsId.length) { useGoodsList.push(i) } })
时间: 2023-05-20 19:02:01 浏览: 88
可以尝试使用 Array.filter() 方法来优化这段代码,如下所示:
let useGoodsList = goodsList.filter(i => item.goodsId.includes(i.id) || !item.goodsId.length);
这样可以避免使用 forEach() 循环,提高代码的执行效率。
相关问题
优化这段代码 let goodsList = [] selectList.forEach(item => { goodsList.push({ price: item.price * item.number, id: item.id }) })
可以使用 map 函数来优化这段代码,如下所示:
let goodsList = selectList.map(item => ({
price: item.price * item.number,
id: item.id
}));
这样可以避免使用 forEach 循环,提高代码的可读性和性能。
let value = localStorage.getItem("goodslist") let list = JSON.parse(value) || [] if (list) { list.array.forEach(element => { //遍历本地存储 if (element.id == this.goodsInfo.id) { element.count += 1 } }); } else { list.push(this.goodsInfo) } localStorage.setItem("goodslist", JSON.stringify(list))
这段代码的作用是将商品信息存储到本地存储。首先,它通过`localStorage.getItem("goodslist")`获取名为"goodslist"的本地存储数据,并将其解析为一个数组。如果本地存储中没有数据,或者解析失败,则将list设置为空数组。
然后,代码会遍历list数组中的每个元素,判断其id是否与当前商品信息的id相等。如果相等,则将该元素的count属性加1。
如果list为空,即本地存储中没有数据,则将当前商品信息(this.goodsInfo)添加到list数组中。
最后,使用`localStorage.setItem("goodslist", JSON.stringify(list))`将更新后的list数组转换成JSON字符串,并存储到名为"goodslist"的本地存储中。
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<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@page import="com.test.bean.Goods,java.util.ArrayList" %> <!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>购物车</title> <style type="text/css"> table{border-collapse:collapse;} td{border:1px solid black; text-align:center; } #deal{margin-left:200px} </style> </head> <body> <jsp:useBean id="cart" class="com.test.bean.Cart" scope="session"></jsp:useBean> <%if(cart==null||cart.getGoodslist().size()==0) out.println("购物车空空如也.....返回商品首页"); else{ ArrayList<Goods>goodslist=cart.getGoodslist(); %> 当前购物车共有<%=cart.getGcount() %>件物品 返回商品首页
序号 商品号 商品名称 价格 数量 小计 描述 <%for(int i=0;i<goodslist.size();i++){ Goods goods=goodslist.get(i); %> <%=i+1 %> <%=goods.getGid() %> <%=goods.getGname() %> <%= String.format("%.2f", goods.getGprice())%> <%=goods.getGcount() %> <%=String.format("%.2f", goods.getGprice()*goods.getGcount()) %> 删除 <%}%>
总计<%=String.format("%.2f",cart.getTotal())%> <input type="button" id="deal" value="购买" /></input> <%}%> <script type="text/javascript"> var dealbutton=document.getElementById("deal"); dealbutton.onclick=function(){ var cf=confirm("确定购买吗?"); if(cf==true){ window.location.href="Servlet/DealServlet"; } } </script> </body> </html> 修改删除功能,在购物车物品数量大于1的情况下点击“删除”时减少1个,等于1时删除此项商品;
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