点名器

代码

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        #box {
            width: 400px;
            height: 100px;
            border: 2px dashed #000;
            text-align: center;
            padding: 30px;
            margin: 50px auto;
        }
    </style>
</head>

<body>
    <div id="box">
        <p>名字</p>
        <button id="start">开始</button> <button id="stop">停止</button>
    </div>
    <script>
        var txt = document.getElementsByTagName('p')[0];
        var btn = document.getElementsByTagName('button');
        var arr = ['孙悟空','猪八戒','红孩儿','蜘蛛精','铁扇公主','嫦娥'];
        var timer = null;
        
        timer = setInterval(auto,100)
        function auto(){
                txt.innerHTML = arr[Math.floor(Math.random()*arr.length)];
        }

        // 开始按钮
        btn[0].onclick = function () {
            clearInterval(timer);
            timer = setInterval(auto,100)
        }

        // 停止按钮
        btn[1].onclick = function () {
            clearInterval(timer);
        }
    </script>
</body>

</html>
点名器

代码

效果
