From: Brian Candler <B.Candler@...>
Date: 2003-07-09T07:39:17+09:00
Subject: Re: Code Snippet: Array.shuffle

On Wed, Jul 09, 2003 at 06:05:28AM +0900, Joe Gwozdecki wrote:
> How come when I try out this code snippet in IRB, including
> entering the array, it does nothing?  Am I missing
> something?

I don't know. Here's an irb session log:

$ irb
irb(main):001:0> class Array
irb(main):002:1> def shuffle
irb(main):003:2> each_index { |i| r = rand(length)
irb(main):004:3>   self[i],self[r] = self[r],self[i] }
irb(main):005:2> end
irb(main):006:1> end
=> nil
irb(main):007:0> a = [1,2,3,4,5,6,7,8,9,10]
=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
irb(main):008:0> a.shuffle
=> [8, 7, 1, 4, 9, 10, 3, 2, 6, 5]
irb(main):009:0> a.shuffle
=> [7, 10, 5, 9, 8, 1, 6, 3, 4, 2]
irb(main):010:0> 

What did you do differently? Note that if you miss a bracket or an 'end'
then irb may think you are in a continuation line; if the prompt ends with
an asterisk this is a pretty strong clue.

irb(main):012:0> [
irb(main):013:1* 1,2,3
irb(main):014:1> ]
=> [1, 2, 3]

Regards,

Brian.