From: Stefano Crocco <stefano.crocco@...>
Date: 2008-04-30T16:23:29+09:00
Subject: Re: Dynamic class instantiation by iteration

On Wednesday 30 April 2008, Frisco Del Rosario wrote:
> I'm curious as to why the following does not create three instances of
> class Cat:
>
>
> class Cat
>    def initialize(name)
>       @name = name
>    end
> end
>
> toons = ["Felix", "Garfield", "Heathcliff"]
>
> toons.each {|t| t = Cat.new(t)}
>
>
> In irb, the last input and output are:
>
> irb(main):008:0> toons.each {|t| t=Cat.new(t)}
> => ["Felix", "Garfield", "Heathcliff"]
>
> which I don't understand.

Your code does create three instances of Cat, but they're thrown away 
immediately, since you don't use them. Array#each always return the receiver 
(in your case, the array ["Felix", "Garfield", "Heathcliff"]), regardless of 
the return value of the block. If you want to obtain an array with the three 
instances of Cat, use Array#map instead:

cats = toons.map{|n| Cat.new(name)}

I hope this helps

Stefano