From: Todd Benson <caduceass@...>
Date: 2007-07-24T06:55:24+09:00
Subject: Re: Variable Generation

On 7/23/07, Ari Brown <ari@aribrown.com> wrote:
> yes, I mean spontaneously generated variables.
>
> Assume we have an array:
>         array = %w(yea cool awesome stuff)
> Now, I'm looking to make a variable corresponding to the item. so that:
>
> yea = "yea"
> cool = "cool"
> awesome = "awesome"
> stuff = "stuff"
>
> My current method (which FAILS) is using eval
> array.each {|item| eval(item + "=\"#{item}\"") }
>
> I tested this with a puts instead of eval, and it comes out exactly
> as it should. But when I try to use the variable, I get a
> undefined local variable or method
> error.
>
> Bwah?

Your new variables only have scope within the block.

I suppose you could do use global variables:

irb> a = %w{ yea cool awesome stuff }
=> ["yea", "cool", "awesome", "stuff"]
irb> a.each { |elem| eval("$" + elem + "=\"#{elem}\"") }
=> ["yea", "cool", "awesome", "stuff"]
irb> $yea
=> "yea"

Yuck.  Is there some reason you couldn't just use a hash, maybe?

irb> h = {}
=> {}
irb> %w{ yea cool awesome stuff }.each { |e| h[e.intern] = e }
=> ["yea", "cool", "awesome", "stuff"]
irb> h[:yea]
=> "yea"

Todd