JavaScript 使用 Math.random 实现课堂随机点名功能详解

<!DOCTYPE html>
<html>
 <head>
  <meta charset="utf-8">
  <title></title>
  <style>
  
   #d2{cursor:pointer;}/*让鼠标移到开始点名的时候变成手型*/
  </style>
 </head>
 <body>
 <div id="d1">亲，准备好了吗？</div> 
  <div id="d2" onclick="fun()">开始点名</div><!--触发事件句柄onlick，调用fun函数-->
  <script>
   
   var mytime=null;
   var d1=document.getElementById("d1");
   var d2=document.getElementById("d2");
   function fun()
   {if(mytime==null)
    {d2.innerHTML="停止点名";
    show();
    
    }
   else {
    
     clearTimeout(mytime);
     d2.innerHTML="开始点名";
     mytime=null;
   }
  }
   function show()
   {var s=["张三","李四","王五","王二","小二"];
    var name=Math.floor(Math.random()*10%s.length);//让name在下标0-4之间取得
    d1.innerHTML=s[name];
    mytime=setTimeout("show()",1);
   
   }
   </script>
  </body>
</html>