From: Hal Fulton <hal9000@...>
Date: 2004-04-06T06:26:28+09:00
Subject: Re: object.@attribute

rolo wrote:
> Why cannot we have attribute access of the object from anywhere in the program by sennding a message @attribute
> 
> class Example
> 	def initialize
> 		@number = '1.0'
> 	end
> end
> 
> e = Example.new
> print e.@number => should print 1.0

That's not how it works.

In Ruby, all data members are private by default. They can be
accessed *only* through methods.

I don't recognize your name offhand. If you are a nuby, you may
not be aware of these possibilities for the class:

     attr_reader :number     # Let outside world read this value
     attr_writer :number     #  "     "       "  set it
     attr_accessor :number   #  "     "       "  read or set it

In practice, I've never used attr_writer. It's hard to imagine
something useful being write-only and not readable. (Insert
Perl wisecrack here.)


Hal