                        课程
                    
                        /前端开发
                        
                            /JavaScript
                        
                        /JavaScript进阶篇

秒数一直往下走

<!DOCTYPE html><html> <head>  <title>浏览器对象</title>    <meta http-equiv="Content-Type" content="text/html; charset=gkb"/>    </head> <body>  <!--先编写好网页布局-->  <h1>操作成功</h1>   <p><span id="clock">5</span>秒后回到主页<a href="javascript:back()">返回</a></p>      <script type="text/javascript">    var num=document.getElementById("clock").innerHTML;    function count(){           num--;            document.getElementById("clock").innerHTML=num;            if(num==0)            {                window.open('https://www.imooc.com','_blank','width=400,height=400');            }                 }      setInterval("count()",1000);       function back(){           window.history.back();       }          </script></body></html>