js随机点名器（简单）

太过爱你忘了你带给我的痛 2023-06-22 20:03 363阅读 0赞

附源代码;

<!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>Document</title>
        <style>
        .box {
            width: 200px;
            height: 200px;
            line-height: 200px;
            background-color: #ccc;
            font-size: 30px;
            text-align: center;
        }
        </style>
    </head>
    <body>
        <div class="box">此乃点名器</div>
        <input type="button" value="点名" id="btn">
        
        <script>
            var btn = document.getElementById("btn");
            var box = document.getElementsByClassName("box")[0];
    // 3、写一个随机抽名的案例？（点击按钮开启定时器，
    // 定时器中去随机抽取人名，把全班的人放在一个数组中，只要想办法获取随机的索引号就可以）
            btn.onclick = function() {
                if(this.value==="点名") {
                function fn() {
                var arr = ["张三","李四","王五","赵六","黑七","白八","紫九","红薯"];
                var index = parseInt(Math.random()*arr.length);
             var n1 = parseInt(Math.random()*255+1);
             var n2 = parseInt(Math.random()*255+1);
             var n3 = parseInt(Math.random()*255+1);
                box.style.background ="rgb("+n1+","+n2+","+n3+")" ;
                box.innerHTML = arr[index]; 
                } 
                this.value = "停止";
                //定时器不加var声明，涉及到作用域问题   
               timer=setInterval(fn,2);
                }else {
                    clearInterval(timer);
                    this.value = "点名";
                }
                
            }
    
    
    
    
            </script>
    </body>
    </html>

效果图如下：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MDg5Mw_size_16_color_FFFFFF_t_70][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MDg5Mw_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20191128000130807.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjE5MDg5Mw==,size_16,color_FFFFFF,t_70