From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2011-03-18T02:03:10+09:00
Subject: Re: Replacing elements in an array?

On Thu, Mar 17, 2011 at 5:56 PM, Jen <jen.bottom@gmail.com> wrote:
> Hello,
>
> This question is following on from my post 'making an array of arrays?', but
> as it is about replacing elements I have started a new thread.
>
> The reply to my last arrays related post did solve one problem, so thanks
> very much for that!
>
> So, I now have an @offspring array that takes copies of @board (a sudoku
> board) according to a population specified by the user.
>
> The aim is to populate all empty cells in @offspring with random numbers,
> but for now I am just populating them with '9'.
> Empty cells were represented by '")', but are now represented by '0'
> Currently the population is fixed at 4, and my current code is:
>
>    def find_empty!
>    #Loop through @offspring and where ever there is "_" put a random number.
>    4.times do |i|
>    if @offspring[i] == 0
>    then @offspring[i] = 9
>    end
>    #For debugging with the test puzzle
>    puts @offspring.inspect
>    end
>
> When I print out offspring I expect the first element to be changed to 9, as
> it was originally set to 0, this is however not the case. I'm sure I'm being
> very dumb, but if someone could please point me in the right direction that
> would be great.
>
> Note I have tried the same thing but using a for loop instead of the .times
> method. This gave me the same results.

Your method works, so maybe @offspring doesn't contain what you think.

ruby-1.8.7-p334 :001 > def find_empty!
ruby-1.8.7-p334 :002?>      #Loop through @offspring and where ever
there is "_" put a random number.
ruby-1.8.7-p334 :003 >        4.times do |i|
ruby-1.8.7-p334 :004 >          if @offspring[i] == 0
ruby-1.8.7-p334 :005?>          then @offspring[i] = 9
ruby-1.8.7-p334 :006?>          end
ruby-1.8.7-p334 :007?>        #For debugging with the test puzzle
ruby-1.8.7-p334 :008 >          puts @offspring.inspect
ruby-1.8.7-p334 :009?>        end
ruby-1.8.7-p334 :010?>   end
 => nil
ruby-1.8.7-p334 :011 > @offspring = [0,0,0,0]
 => [0, 0, 0, 0]
ruby-1.8.7-p334 :012 > find_empty!
[9, 0, 0, 0]
[9, 9, 0, 0]
[9, 9, 9, 0]
[9, 9, 9, 9]
 => 4
ruby-1.8.7-p334 :013 > @offspring
 => [9, 9, 9, 9]

Can you add the inspecting puts at the beginning of the method and
show us the result?

Jesus.