From: Morton Goldberg <m_goldberg@...>
Date: 2007-11-12T13:03:15+09:00
Subject: Re: [noob] name of a variable, at runtime


On Nov 11, 2007, at 10:30 PM, Colin Summers wrote:

> This seems harder than the usual thing I've been tripping on (and
> finding answers in the pickaxe or online).
>
> I have an object: human. It has parts: human.hand human.foot.
>
> How can I say this:
>     fred = human.new
>     fred.hand  = fred.foot = fred. leg = 'flesh'
>     fred.knee = 'plastic'
>     fred.head = 'steel'
>     parts = [hand,foot,leg,knee]
>     parts.each do |part|
>         puts "part #{part} is made of " + fred.{part}.to_s
>     end # with each part
>
> Am I close?

Close, yes, but not quite there. Assuming you want to roll your own  
Human class, then you can do something like:

<code>
class Human
    attr_accessor :hand, :leg, :foot, :head, :knee
end

fred = Human.new
fred.hand = fred.foot = fred.leg = 'flesh'
fred.knee = 'plastic'
fred.head = 'steel'
parts = %w[hand foot leg knee]
parts.each do |part|
     puts "part #{part} is made of #{fred.send(part)}"
end
</code>

OTOH, you might look at the built-in Struct class. It may do  
everything you want.

Regards, Morton