From: "Peter v. N." <skull2crush@...>
Date: 2005-10-12T08:31:53+09:00
Subject: Re: multi-dimensional Arrays

I got that! Your explanation is clear & simple.

I'm really astonished as how fast everyone responds here.

Thank you all..and wait for more to come from my side ;-)


David A. Black wrote:
> Hi --
> 
> On Wed, 12 Oct 2005, Peter v. N. wrote:
> 
>> 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))
> 
> 
> In the first one, the block is executed once each time to fill up the
> array.  It's like:
> 
>   arr = [Array.new(3),Array.new(3),Array.new(3)]
> 
> So it's an array of three different arrays.
> 
> The second one sets all three initial values to the *same* array.
> It's like:
> 
>   inner = Array.new(3)
>   arr = [inner,inner,inner]
> 
> So you've got an array of three copies of the same object, which of
> course has major implications when you modify that object, etc.
> 
> 
> David
>