end andSelf 区别

1. $(document).ready(function(){  
2.       
3.     jQuery.fn.showTags = function (n) {  
4.       var tags = this.map(function () {   
5.                               return this.tagName;   
6.                             })  
7.                         .get().join(", ");  
8.       $("b:eq(" + n + ")").text(tags);  
9.       return this;  
10.     };  
11.   
12.     $("p").showTags(0)  
13.           .find("span")  
14.           .showTags(1)  
15.           .css("background", "yellow")  
16.           .end()  
17.           .showTags(2)  
18.           .css("font-style", "italic");  
19.   
20.   });  

<p>
    Hi there <span>how</span> are you <span>doing</span>?
  </p>
  <p>
    This <span>span</span> is one of
    several <span>spans</span> in this
    <span>sentence</span>.
  </p>
  <div>
    Tags in jQuery object initially: <b></b>
  </div>
  <div>
    Tags in jQuery object after find: <b></b>
  </div>
  <div>
    Tags in jQuery object after end: <b></b>
  </div>

 

end()
将返回到执行find("span")操作之前的匹配元素集合状态

 

$("div").find("p").andSelf().addClass("border");
将匹配div元素集合增加到匹配p元素集合中。