From: Julian Leviston <julian@...>
Date: 2005-08-25T07:59:39+09:00
Subject: Re: determining the attribute names of an object

Yeah,

Instance variables are a concern of the developer of the object, but  
attributes are a concern of the user of the object.

Julian.


On 25/08/2005, at 12:53 AM, James Edward Gray II wrote:

> On Aug 24, 2005, at 9:43 AM, Mark Volkmann wrote:
>
>
>> I really don't get this. Can you give a definition of each of the
>> terms "instance variable" and "attribute"?  I'm pretty sure most
>> people that have been doing OO development for years would say that
>> they thought those were the same thing. Maybe many of us were  
>> sleeping
>> in class when those concepts were taught. ;-)
>>
>
> Well, here's an example:
>
> class Name
>     def initialize( first, last )
>         @first, @last = first, last
>     end
>
>     attr_accessor :first, :last
>
>     def full_name
>         "#{@first} #{@last}"
>     end
>
>     def full_name=( name )
>         @first, @last = name.split
>     end
> end
>
> I would say that the above class has a full_name attribute, but it  
> certainly does not have a @full_name instance variable.
>
> Hope that helps.
>
> James Edward Gray II
>
>
>