From: Subbu <subramani.athikunte@...>
Date: 2008-03-25T14:54:57+09:00
Subject: Re: generating unique random numbers

On Mar 24, 6:05 pm, Tim Hunter <TimHun...@nc.rr.com> wrote:
> Jimmy Palmer wrote:
> > I'm trying to generate 8 unique random numbers between 1 and 13.
>
> > for example my first set of results could be:
>
> > 2, 8, 4, 6, 3, 10, 12, 1
>
> > the results need to be between 1 and 13 and they must be unique.
>
> > The rand(12) + 1 returns random numbers between 1 and 13, but they are
> > not unique.  Any quick solutions?
>
> ~$ irb
> irb(main):001:0> (1..13).to_a.sort_by{rand}[0..7]
> => [7, 3, 8, 2, 11, 4, 1, 9]
> irb(main):002:0>
>
> --
> RMagick:http://rmagick.rubyforge.org/
> RMagick 2:http://rmagick.rubyforge.org/rmagick2.html

Hey Tim, I am a bit lost here :) sort_by accepts a block. But I see
you are just passing it a method. How does this work? Does Ruby
convert the return value of the method to a block and then sorts it?
Do you mind explaining it for me? Thanks so much.