From: Joel VanderWerf <joelvanderwerf@...>
Date: 2010-04-25T06:48:14+09:00
Subject: Re: Metaprogramming - Array initialization

Paul A. wrote:
> Hi,
> 
> In Ruby, we can declare array as explain in the doc:
> http://ruby-doc.org/core/classes/Array.html#M002150
> 
> That makes possible many kind of use, such as:
>>> Array.new(1, Array.new(3, Array.new(2, Array.new(1))))
> => [[[[nil], [nil]], [[nil], [nil]], [[nil], [nil]]]]
> 
> For my needs, I would like to use a code that declare an array of any
> arrays that we want. I don't know if it is possible.

The above is probably not what you want. Look:

 >> a=Array.new(3, Array.new(2))
=> [[nil, nil], [nil, nil], [nil, nil]]
 >> a[0][1] = 6
=> 6
 >> a
=> [[nil, 6], [nil, 6], [nil, 6]]

Try using the block form:

 >> a=Array.new(3) {Array.new(2)}
=> [[nil, nil], [nil, nil], [nil, nil]]
 >> a[0][1] = 6
=> 6
 >> a
=> [[nil, 6], [nil, nil], [nil, nil]]