From: "Peter v. N." <skull2crush@...>
Date: 2005-10-12T06:56:52+09:00
Subject: Re: multi-dimensional Arrays

Thank you for all the replies! This is really great.

But I still wonder (or play dumb here):

what's the difference between

arr = Array.new(3) { Array.new(3) }

	and

arr = Array.new(3, Array.new(3))


Brian Schr�der wrote:
> On 11/10/05, Peter v. N. <skull2crush@hotmail.com> wrote:
> 
>>Hi all,
>>
>>I'm a Ruby noob so please forgive me...
>>
>>I know there exist "simple" ways (Google's thy friend)
>>to create md arrays with Ruby. But it's somehow cumbersome
>>and it would be nice if it could be done like "array = Array.new(3,3)"
>>-> I know too that this means not the same in Ruby...
>>
>>What I like to know: what led to the decission to do it that way
>>and not like it is done in the C/C++ (Java) languages � la
>>"int[][] arr = new int[3][3]"?
> 
> 
> you do it the same as in c, you say that you want an array of arrays.
> E.g.
> 
> arr = Array.new(3) { Array.new(3) }
> 
> which is the same as int[3][3] in c where iirc int[3][3] is not a
> contiguous block of memory but pointers to arrays. If you want a
> contiguous block of memory maybe narray can help you.
> 
> 
>>Maybe because this approach is not strictly oo-oriented? But then,
>>switches and loops in Ruby are neither.
> 
> 
> In my opinion this has nothing to do with oo versus non oo. Switches
> and loops are signs of imperative programming, which is oppsite to
> functional and logical programming but orthogonal to object oriented
> versus not object oriented.
> 
> 
>>It's just the devil inside who likes to know about the philosophy
>>about the "why it is done like that" and I'm not bitching about
>>Ruby (by no means).
>>
>>Thank you for a pointer or a short explanation.
>>
>>Greetings,
>>Peter
>>
>>
> 
> 
> And beware that
> Array.new(3, Array.new(3)) is not the same as Array.new(3) { Array.new(3) }
> 
> hope to help,
> 
> Brian
> 
> --
> http://ruby.brian-schroeder.de/
> 
> Stringed instrument chords: http://chordlist.brian-schroeder.de/
> 
>