From: Armin Armbruster <aarmbruster@...>
Date: 2007-08-01T04:43:02+09:00
Subject: Re: Unexpected behavior with multidimensional arrays

Dan Zwell wrote:
> 
> The above does the same thing as ary = Array.new(3, []), but needs one
> more line of code.
> 
> What does everyone think?
> 
> Dan

Hmm,

I guess my brain is still too much C-wired, but as Dan mentioned so are 
the brains of many others. Looks like a pretty frequent mistake to me.
I can't think of a real world example where the current implementation 
of Array.new(3,[]) is usefull, but then I don't use arrays of Classes.
It's like in C having an array of pointers that all point to the same 
address.

To use Dan's example, if you continue with

irb(main):005:0> ary[1] << "by"
=> ["hi", "by"]
irb(main):006:0> ary
=> [["hi", "by"], ["hi", "by"], ["hi", "by"]]

but obviously that's not what I intended to do (and we already discussed 
the solution how to do it right).

Again, if anybody can come up with a simple and halfway applied example 
in which the current behavior is useful I would appreciate the 
enlightenment very much.

Thanks,
Armin
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