js学习笔记之公告逐行显示

 $(function(){
     var newsListHeight = $(".news-list").height(); //获得内容的高度
     var newsConHeight = $(".news-con").innerHeight();//获得外层的高度
     var rows = 1;//初始化当前行为第一行
     setInterval(function(){
         var nowtop = - rows * newsConHeight;
         $(".news-list").css("top",nowtop);
         rows++
         if(rows * newsConHeight >= newsListHeight){ rows = 0;}
     },3000);
 });