<!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>随机抽查</title>
</head>
<body>
<button id="ran">随机抽查一位同学</button>
<script>
var btn = document.getElementById("ran");
btn.addEventListener("click", function () {
var str = ["张三", "李四", "孔二"];
var num = parseInt(Math.random() * ((str.length - 1) + 1));
var newstr = str[num];
alert(newstr);
})
</script>
</body>
</html>
