window.onload与$()/$(document).ready()的区别

验证执行时机代码：

 

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title></title>
<script src="../../scripts/jquery.js" type="text/javascript"></script>
<script type="text/javascript">
   var startTime = new Date().getTime();

  function test1(){
      var endTime2  = new Date().getTime(); 
      var a = endTime2 - startTime;
      $("<div>jQuery的ready() : "+a+" ms</div>").appendTo("body");
  }

  function test2(){
       var endTime1  = new Date().getTime();
       var b = endTime1 - startTime;
       $("<p>JavaScript的window.onload : "+b+" ms</p>").appendTo("body");
  }
  //页面依赖的图片加载完毕才执行window.onload函数
   window.onload=function(){
        test2();
   }
  //文档对象树绘制完毕就执行$(funciton(){})函数
   $(document).ready(function(){
        test1();
  })
    
</script>
</head>
<body>
    <img src="demo.jpg" style="width:200px;height:200px;"/>
</body>
</html>

 

posted @ 2018-09-28 09:57  程序员008  阅读(162)  评论(0)  编辑  收藏  举报