要求
一、结合抽奖案例完成随机点名程序，要求如下:
1.点击点名按钮，名字界面随机显示，按钮文字由点名变为停止
2.再次点击点名按钮，显示当前被点名学生姓名，按钮文字由停止变为点名
3.样式请参考css及html*发挥完成。
代码
<!DOCTYPE html>
<html lang="en">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>随机点名</title>
<style>
*{
margin-left: 0px;
margin-top: 0px;
}
.container{
width: 600px;
height: 600px;
border: 1px solid yellow;
position: absolute;
left: 50%;
margin-left: -400px;
text-align: center;
line-height: 100px;
}
.box,.box2{
width: 300px;
height: 300px;
background-color: pink;
margin: auto;/*水平距离的居中*/
margin-top: 50px;
line-height: 300px;
}
.box2{
background-color: aqua;
}
#show{
font-size: 30px;
color: aliceblue;
font-weight: bold;
} #start{
width: 300px;
height: 50px;
background-color:aquamarine ;
}
</style>
</head>
<body>
<div class="container">
<div class="box" id="box">
<span id="show">姓名</span>
</div>
<button id="start" onclick="change()">点名</button>
</div>
</body>
</html>
<script>
//标志位
var flag=false
var awards=["张三","李四","王五","赵六","钱七","孙八"]
//2.获取对应dom对象
var box=document.getElementById("box")
var show=document.getElementById("show")
var start=document.getElementById("start")
//3.定义定时器
var timer
//4.点击事件触发
function change(){
if(!flag){
flag=true
start.innerHTML="停止点名"
timer=setInterval(function(){
// --- 获取匹配姓名数组的索引随机数
let index = Math.floor(Math.random()*awards.length)
show.innerHTML=awards[index]
box.setAttribute("class","box2")
},10)
} else{
flag=false
start.innerHTML="开始点名"
clearInterval(timer)
box.setAttribute("class","box")
}
}
</script>演示
