1、什么是事件冒泡
答：事件冒泡是指事件的响应会像水泡一样上升至最顶级对象，我们把这个特性就称之为事件冒泡。
例1：事件冒泡程序
<!DOCTYPE html> <html> <head> <meta charset=’utf-8′> <title></title> <style type=”text/css”> div#div1{ width:500px; height:500px; background:red; } div#div2{ width:400px; height:400px; background:blue; } div#div3{ width:300px; height:300px; background:yellow; } </style> <script src=”public.js”></script> <script> window.onload = function(){ addEvent($(‘div1′),’click’,function(){ alert(‘div1′); }) addEvent($(‘div2′),’click’,function(){ alert(‘div2′); }) addEvent($(‘div3′),’click’,function(){ alert(‘div3′); }) } </script> </head> <body> <div id=”div1″> <div id=”div2″> <div id=’div3′></div> </div> </div> </body> </html>