<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
<style>
body{
background-color: aliceblue;
}
.box{
width: 1000px;
height: 240px;
/*background-color: aqua;*/
margin: 0 auto;
margin-top: 100px;
clear: both;
}
#btn{
width: 100px;
height: 30px;
margin-left: 600px;
margin-top: 50px;
}
.name{
width: 100px;
height: 30px;
float: left;
background-color: antiquewhite;
margin-left: 10px;
margin-top: 10px;
text-align: center;
line-height: 30px;
}
#span{
float: right;
position: relative;
top: 55px;
right: 185px;
}
h1{
text-align: center;
}
</style>
</head>
<body>
<h1>随机点名系统</h1>
<span id="span"></span>
<div class="box" id="box"></div>
<input type="button" id="btn" value="点名"/>
<span id="_span"></span>
<script>
// 获取id函数
function my$(id){
return document.getElementById(id)
};
// 模拟后台数据
var arr = ["吉帆","静慧","嘉歆","金枝","王大妈","老王","刘疙瘩","杨伟",
"韩晁","静涵","静曼","晶晶","靓影","嘉宝","李静","李志","李伟","家美"
,"金枝","静恬","刘泽祥","静和","晶灵","立超","嘉懿","王欢","王欣","郭琦"
,"嘉美","王琦","洁静","小杨","佳思","吉玉","张焕","张赛","娟秀","菊月"
,"王晶","吉玟","王飞","皎洁","曾艳","王翠青"
];
// 动态创建层
for(var i =0;i<arr.length;i++){
var div = document.createElement("div");
div.innerText=arr[i];
div.className="name";
my$("box").appendChild(div);
};
var _index;
// 点名
my$("btn").onclick=function(){
var peoples= arr.length;
// 监视按钮的状态
if(this.value==="点名"){
// 定时针
timeId=setInterval(function () {
// 清空所有层的颜色
for(var i =0;i<arr.length;i++){
my$("box").children[i].style.background=""
};
// 留下当前层的颜色
var random = parseInt(Math.random()*peoples);
my$("box").children[random].style.background="red";
// _span
my$(‘_span‘).innerText = arr[random];
_index = random;
},100);
this.value="停止";
}else{
my$(‘_span‘).innerText = arr[_index];
// 清除计时器
clearInterval(timeId);
this.value="点名";
};
};
// 获取时间的函数
getTime();
setInterval(getTime,1000)
function getTime(){
var day = new Date();
var year = day.getFullYear();//年
var month = day.getMonth()+1;//月
var dat = day.getDate();//日
var hour = day.getHours();//小时
var minitue = day.getMinutes();//分钟
var second = day.getSeconds();//秒
month=month<10?"0"+month:month;
dat=dat<10?"0"+dat:dat;
hour=hour<10?"0"+hour:hour;
minitue=minitue<10?"0"+minitue:minitue;
second=second<10?"0"+second:second;
my$("span").innerText=year+"-"+month+"-"+dat+" "+hour+":"+minitue+":"+second
}
</script>
</body>
</html>
总结：
主要是利用定时器，点击开始IDE时候不断的执行，并同时生成随机数，利用数组的下标完成展示。
主要用到的知识点：setInterval,Math.random()
原文：https://www.cnblogs.com/xiaomili/p/10700496.html