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7.14练习案例总结

news 2025/7/15 16:31:40

文章目录

要点总结
实例
- - 随机点名
  - 轮播图

要点总结

api部分

获取对象
const 对象名=document.querySelector('选择器')
间歇函数
setInterval(函数名,间隔时间)返回值为对应id用于结束（clearInterval）
间歇函数由于系统限制问题导致设置为1时会不准确（强制向上取最小值4 ms、5 ms 甚至更高）并且每次的误差不确定
事件监听
对象名.addEventListener(事件类型,方法)
自定义用data-
dataset会去重以第一个为主
dom树图

算法部分

在函数前可用如下指定参数类型等

/*** @param {number} start* @param {number} len* @param {string} path* @param {string[]} ret* @return {void}*/

js字符串无法修改

实例

随机点名

用事件监听实现表单交互功能，

间歇函数和随机数实现生成随机人名

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head>
<body><style>.nav {margin-top:  125px;height:auto;}.head{height: 80px;background-color: aliceblue;line-height: 80px;font-size: 40px;padding-left: 200px;}button{width: 100px;height: 50px;font-size: 30px;line-height: 50px;}.btn{padding-left: 500px;}.exit{margin-left: 50px;}</style><div class="nav"><div class="head">姓名:<span></span></div><div class="btn"> <button class="start">开始</button><button class="exit">结束</button></div></div><script>let arr=["荀彧", "荀攸", "贾诩", "郭嘉", "程昱", "戏志才", "刘晔", "蒋济", "陈群", "华歆", "钟繇", "满宠", "董昭", "王朗", "崔琰", "毛玠", "杜畿", "田畴", "王修", "杨修", "辛毗", "杨阜", "田豫", "王粲", "蒯越", "张继", "杜袭", "枣祗"]// 随机数函数function getRandom(){return parseInt(Math.random()*arr.length)}// 姓名栏const sp=document.querySelector(`.head span`)// 按钮const start=document.querySelector(`.start`)const exit =document.querySelector(`.exit`)// 间歇函数idlet timeid=0 //    flaglet startflag=false;// 开始函数function startway(){timeid = setInterval(function(){sp.innerHTML=arr[getRandom()]},15)startflag=true;if(startflag){start.disabled=true;}}// 结束函数function exitway(){clearInterval(timeid)startflag=falsestart.disabled=false;}// 事件监听start.addEventListener('click',startway)exit.addEventListener('click',exitway)</script>
</body>
</html>

轮播图

根据课程重写了此部分三次
第一次实现刷新切换随机图
第二次实现定时轮播
第三次实现表单交互

<!DOCTYPE html>
<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>轮播图点击切换</title><style>* {box-sizing: border-box;}.slider {width: 560px;height: 400px;overflow: hidden;}.slider-wrapper {width: 100%;height: 320px;}.slider-wrapper img {width: 100%;height: 100%;display: block;}.slider-footer {height: 80px;background-color: rgb(100, 67, 68);padding: 12px 12px 0 12px;position: relative;}.slider-footer .toggle {position: absolute;right: 0;top: 12px;display: flex;}.slider-footer .toggle button {margin-right: 12px;width: 28px;height: 28px;appearance: none;border: none;background: rgba(255, 255, 255, 0.1);color: #fff;border-radius: 4px;cursor: pointer;}.slider-footer .toggle button:hover {background: rgba(255, 255, 255, 0.2);}.slider-footer p {margin: 0;color: #fff;font-size: 18px;margin-bottom: 10px;}.slider-indicator {margin: 0;padding: 0;list-style: none;display: flex;align-items: center;}.slider-indicator li {width: 8px;height: 8px;margin: 4px;border-radius: 50%;background: #fff;opacity: 0.4;cursor: pointer;}.slider-indicator li.active {width: 12px;height: 12px;opacity: 1;}</style>
</head><body><div class="slider"><div class="slider-wrapper"><img src="./images/slider01.jpg" alt="" /></div><div class="slider-footer"><p>对人类来说会不会太超前了？</p><ul class="slider-indicator"><li></li><li></li><li></li><li></li><li></li><li></li><li></li><li></li></ul><div class="toggle"><button class="prev">&lt;</button><button class="next">&gt;</button></div></div></div><script>// 1. 初始数据const sliderData = [{ url: './images/slider01.jpg', title: '对人类来说会不会太超前了？', color: 'rgb(100, 67, 68)' },{ url: './images/slider02.jpg', title: '开启剑与雪的黑暗传说！', color: 'rgb(43, 35, 26)' },{ url: './images/slider03.jpg', title: '真正的jo厨出现了！', color: 'rgb(36, 31, 33)' },{ url: './images/slider04.jpg', title: '李玉刚：让世界通过B站看到东方大国文化', color: 'rgb(139, 98, 66)' },{ url: './images/slider05.jpg', title: '快来分享你的寒假日常吧~', color: 'rgb(67, 90, 92)' },{ url: './images/slider06.jpg', title: '哔哩哔哩小年YEAH', color: 'rgb(166, 131, 143)' },{ url: './images/slider07.jpg', title: '一站式解决你的电脑配置问题！！！', color: 'rgb(53, 29, 25)' },{ url: './images/slider08.jpg', title: '谁不想和小猫咪贴贴呢！', color: 'rgb(99, 72, 114)' },]// 生成随机数let random = parseInt(Math.random()*sliderData.length)console.log(sliderData[random])//获取图片const img =document.querySelector(`.slider-wrapper img`)// 修改路径img.src=sliderData[random].url// 更换pconst p =document.querySelector(`.slider-footer p`)p.innerHTML=sliderData[random].title// 改背景颜色const footer =document.querySelector('.slider-footer');footer.style.background=sliderData[random].color// 改点const li=document.querySelector(`.slider-indicator li:nth-child(${random+1})`)li.classList.add('active')// 以上为第一次// 逐个变化//删除函数function delt(){let now=document.querySelector('.active')now.classList.remove('active')}// 变化函数function change(){// 变图const nowimg=document.querySelector(`.slider-wrapper img`)nowimg.src=sliderData[random].url// 变pconst nowp=document.querySelector(`.slider-footer p`)p.innerHTML=sliderData[random].title// 变背景const nowfoot=document.querySelector(`.slider-footer`)nowfoot.style.background=sliderData[random].color// 变点const nowli=document.querySelector(`.slider-indicator li:nth-child(${random+1})`)nowli.classList.add('active')}// 选择函数function runtime(){delt()random= (random+1)%sliderData.lengthchange()}let runid= setInterval(runtime,1000)// 以上为第二次</script><script>// 事件监听，放置则暂停const slider=document.querySelector(`.slider`)slider.addEventListener('mouseenter',function(){clearInterval(runid)})// 离开继续slider.addEventListener('mouseleave',function(){runid=setInterval(runtime,1000)})// 按钮监听const prev=document.querySelector(`.prev`)prev.addEventListener('click',function(){delt()if(random-1<0){random=7;}else{random= (random-1)%sliderData.length}change()})// 下一个const next=document.querySelector(`.next`)next.addEventListener('click',function(){delt()random= (random+1)%sliderData.lengthchange()})// 以上为第三次</script>
</body></html>