<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta h...
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>随机点名</title>
<style>
#content{
width: 600px;
height: 400px;
background: #000;
margin: 100px auto;
text-align: center;
position: relative;
line-height: 300px;
color: dodgerblue;
font-size: 70px;
}
#btn1{
background: #ccc;
width: 180px;
height: 80px;
font-size: 30px;
color: #f40;
border-radius: 12px;
position: absolute;
bottom: 30px;
left: 50%;
margin-left: -90px;
}
</style>
</head>
<body>
<div id="content">
<span id="span1">
点击开始
</span>
<button id="btn1">
start
</button>
</div>
<script>
var arr = ['中国','英国','德国','美国','意大利','法国','西班牙','日本','阿联酋','荷兰','葡萄牙'];
var $btn1 = document.getElementById('btn1');
var $content = document.getElementById('content');
var $span1 = document.getElementById('span1');
var timer;//计时器
var testNum = true;
$btn1.onclick = function(){
if(testNum){
// console.log(1);
start();
$btn1.innerHTML = 'stop';
testNum = false;
}
else{
// console.log(0);
stop();
$btn1.innerHTML = 'start';
testNum = true;
}
}
function start(){
timer = setInterval(function(){
var num = random(0,arr.length - 1);
$span1.innerHTML = arr[num];
},50)
}
function stop(){
clearInterval(timer);
}
// 随机函数
function random(a,b){
var randomNum = Math.round(Math.random() * (b - a) + a);
return randomNum;
}
</script>
</body>
</html>
