From: Jason Creighton <androflux@...>
Date: 2003-07-08T11:02:09+09:00
Subject: Re: Code Snippet: Array.shuffle

On 08 Jul 2003 03:01:30 +0200
Stefan Arentz <stefan.arentz@soze.com> wrote:

> 
> Here is another small Ruby code snippet that extends the Array class. Use
> this to randomize the order of all entries in an Array.
> 
>  class Array
>    def shuffle
>      self.each_index { |i| r = rand(self.length - 1);
>          self[i],self[r] = self[r],self[i] }
>    end
>  end
> 
> Works like this:
> 
>  a = Array[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>  a.shuffle
>    ==> [7, 10, 9, 6, 4, 8, 5, 3, 1, 2]

>> ary = (0..10).to_a
=> [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>> ary.sort { rand(3)-1 }
=> [4, 6, 5, 0, 2, 3, 9, 7, 8, 1, 10]

.....of course, this probably won't produce as random as result, but it's easier to implement.

Jason Creighton