JS进阶 Day02
1.深入对象
2.构造函数
3.new 实例化执行过程
4.实例成员和静态成员
5.基本包装类型
6.Object静态方法
7.数组reduce累计方法
reduce如何实现数组累加的
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<html lang="en"><head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head><body><script>const arr = [{name: '张三',salary: 10000}, {name: '李四',salary: 10000}, {name: '王五',salary: 20000},]// 涨薪的钱数 10000 * 0.3 // const money = arr.reduce(function (prev, item) {// return prev + item.salary * 0.3// }, 0)const money = arr.reduce((prev, item) => prev + item.salary * 0.3, 0)console.log(money)</script>
</body></html>8.数组find、every和转换为真数组
9.字符串常见方法
10.渲染赠品案例
根据上图代码写成一行
11.综合案例-购物车案例渲染数据
12.综合案例-购物车案例合计模块
总代码：
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<html lang="en"><head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title><style>* {margin: 0;padding: 0;box-sizing: border-box;}.list {width: 990px;margin: 100px auto 0;}.item {padding: 15px;transition: all .5s;display: flex;border-top: 1px solid #e4e4e4;}.item:nth-child(4n) {margin-left: 0;}.item:hover {cursor: pointer;background-color: #f5f5f5;}.item img {width: 80px;height: 80px;margin-right: 10px;}.item .name {font-size: 18px;margin-right: 10px;color: #333;flex: 2;}.item .name .tag {display: block;padding: 2px;font-size: 12px;color: #999;}.item .price,.item .sub-total {font-size: 18px;color: firebrick;flex: 1;}.item .price::before,.item .sub-total::before,.amount::before {content: "¥";font-size: 12px;}.item .spec {flex: 2;color: #888;font-size: 14px;}.item .count {flex: 1;color: #aaa;}.total {width: 990px;margin: 0 auto;display: flex;justify-content: flex-end;border-top: 1px solid #e4e4e4;padding: 20px;}.total .amount {font-size: 18px;color: firebrick;font-weight: bold;margin-right: 50px;}</style>
</head><body><div class="list"><!-- <div class="item"><img src="https://yanxuan-item.nosdn.127.net/84a59ff9c58a77032564e61f716846d6.jpg" alt=""><p class="name">称心如意手摇咖啡磨豆机咖啡豆研磨机 <span class="tag">【赠品】10优惠券</span></p><p class="spec">白色/10寸</p><p class="price">289.90</p><p class="count">x2</p><p class="sub-total">579.80</p></div> --></div><div class="total"><div>合计：<span class="amount">1000.00</span></div></div><script>const goodsList = [{id: '4001172',name: '称心如意手摇咖啡磨豆机咖啡豆研磨机',price: 289.9,picture: 'https://yanxuan-item.nosdn.127.net/84a59ff9c58a77032564e61f716846d6.jpg',count: 2,spec: { color: '白色' }},{id: '4001009',name: '竹制干泡茶盘正方形沥水茶台品茶盘',price: 109.8,picture: 'https://yanxuan-item.nosdn.127.net/2d942d6bc94f1e230763e1a5a3b379e1.png',count: 3,spec: { size: '40cm*40cm', color: '黑色' }},{id: '4001874',name: '古法温酒汝瓷酒具套装白酒杯莲花温酒器',price: 488,picture: 'https://yanxuan-item.nosdn.127.net/44e51622800e4fceb6bee8e616da85fd.png',count: 1,spec: { color: '青色', sum: '一大四小' }},{id: '4001649',name: '大师监制龙泉青瓷茶叶罐',price: 139,picture: 'https://yanxuan-item.nosdn.127.net/4356c9fc150753775fe56b465314f1eb.png',count: 1,spec: { size: '小号', color: '紫色' },gift: '50g茶叶,清洗球,宝马, 奔驰'}]// 1. 根据数据渲染页面document.querySelector('.list').innerHTML = goodsList.map(item => {// console.log(item) // 每一条对象// 对象解构 item.price item.countconst { picture, name, count, price, spec, gift } = item// 规格文字模块处理const text = Object.values(spec).join('/')// 计算小计模块 单价 * 数量 保留两位小数 // 注意精度问题，因为保留两位小数，所以乘以 100 最后除以100const subTotal = ((price * 100 * count) / 100).toFixed(2)// 处理赠品模块 '50g茶叶,清洗球'const str = gift ? gift.split(',').map(item => `<span class="tag">【赠品】${item}</span> `).join('') : ''return `<div class="item"><img src=${picture} alt=""><p class="name">${name} ${str} </p><p class="spec">${text} </p><p class="price">${price.toFixed(2)}</p><p class="count">x${count}</p><p class="sub-total">${subTotal}</p></div>`}).join('')// 3. 合计模块const total = goodsList.reduce((prev, item) => prev + (item.price * 100 * item.count) / 100, 0)// console.log(total)document.querySelector('.amount').innerHTML = total.toFixed(2)</script>
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