Newbie question: Referring to element by class

Newbie question: Referring to element by class

Hi,

Can anyone offer me some explanation as to selecting an element by class name? In an online example this template code is give for a button element:

[code]

 <button data-catid="{{category.id}}" data-title="{{ result.title }}" data-url="{{ result.link }}" class="rango-add btn btn-mini btn-info" type="button">Add</button>
                                 
[/code]

So there is no element id, but there is a class name of  "rango-add btn btn-mini btn-info". The example jquery ajax code is given as follows:

[code] 

  

   $
   (
   '.rango-add'
   ).
   click
   (
   function
   (){
  

  
 
   var 
   catid 
   = 
   $
   (
   this
   ).
   attr
   (
   "data-catid"
   );
  

  

           
   var 
   url 
   = 
   $
   (
   this
   ).
   attr
   (
   "data-url"
   );
  

  

           
   var 
   title 
   = 
   $
   (
   this
   ).
   attr
   (
   "data-title"
   );
  

  

           
   var 
   me 
   = 
   $
   (
   this
   )
  

  
 
   $
   .
   get
   (
   '/rango/auto_add_page/'
   , 
   {
   category_id
   : 
   catid
   , 
   url
   : 
   url
   , 
   title
   : 
   title
   }, 
   function
   (
   data
   ){
  

  
 
   $
   (
   '#pages'
   ).
   html
   (
   data
   );
  

  
 
   me
   .
   hide
   ();
  

  
 
   });
  

  
 
   });

[/code]


To me the event handler is looking out for the class "rango-add" which surely is different to  "rango-add btn btn-mini btn-info".

Why does this work?

Thanks,


Andy