From: dblack@...
Date: 2006-08-12T21:26:48+09:00
Subject: Re: newbie question: how to create variable

Hi --

On Sat, 12 Aug 2006, Mr Pinto wrote:

> On Aug 11, 2006, at 12:55 PM, Robert Klemme wrote:
>
>> Karel Michek wrote:
>>> Hi,
>>> how to create variable in the method that accepts string as name of the 
>>> variable and the object? Something like this:
>>> class InterpreterCallback     def set_object(name, value)
>>> #do something here
>> 
>> instance_variable_set("@#{name}", value)
>>>    end
>>> end
>>> $callback = InterpreterCallback.new()
>>> $callback.set_object("var", 3)
>>> puts var
>>>>>> 3
>
> Depending on what you're trying to do, you might be able to use a simple eval 
> statement:
> irb(main):001:0> name="var"
> => "var"
> irb(main):002:0> value="3"
> => "3"
> irb(main):003:0> eval "#{name} = value"
> => "3"
> irb(main):004:0> var
> => "3"

That only works in irb.  With ruby you'll get:

  ruby -e 'name="var"; value="3"; eval("#{name}=#{value}"); var'
   -e:1: undefined local variable or method `var' for main:Object
   (NameError)


David

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