From: Ned Konz <ned@...>
Date: 2001-10-20T01:39:20+09:00
Subject: [ruby-talk:22760] Re: Creating variables with dynamic names ?

On Friday 19 October 2001 09:25 am, Andrew Cowan wrote:
> I am somewhat new to Ruby, coming from about 10 years of Perl programming,
> 6 professionally.
>
> In perl, it is easy to create new variables with variable names that are
> defined in another variable. For example:
>
> $var_name = "myVar";
> ${"$var_name"} = 10;
>
> would define a new variable $myVar the value 10.

The usefulness of this is quite limited, unless you're writing an interactive 
environment. Many people just say

       use strict;

at the top of their Perl programs and get away with it. And the 
symbolic references like the above will be flagged with warnings.

> Is there a way to do this in Ruby? I suspect there must be but haven't been
> able to figure this out yet.

There's eval, instance_eval, etc.

$ irb
irb(main):001:0> a = "abc"
"abc"
irb(main):002:0> instance_eval a + "=3"
3
irb(main):003:0> abc
3

-- 
Ned Konz
currently: Stanwood, WA
email:     ned@bike-nomad.com
homepage:  http://bike-nomad.com