Rails console

I tried to create an addition to Enumerable called choose_randomly
that picks a random element from the Enumerable object. However when I
define it and execute the code rand complains about the wrong number
of arguments. Below is a capture of the ./script/console session.

farrel@nicodemus ~/Work/GreenGreen/Code/green_green_client_application
$ ./script/console
Loading development environment (Rails 2.1.2)

[1,2,3].choose_randomly

NoMethodError: undefined method `choose_randomly' for [1, 2, 3]:Array
  from (irb):1

module Enumerable
  def choose_randomly
    array_of_self = Array( self )
    index = rand( array_of_self.size )
    array_of_self[ index ]
  end
end

=> nil

[1,2,3].choose_randomly

ArgumentError: wrong number of arguments (1 for 0)
  from (irb):5:in `rand'
  from (irb):5:in `choose_randomly'
  from (irb):9

[1,2,3][ rand( [1,2,3].size )]

=> 1

As you can see if I execute the code myself it seems to work. If I
copy that same code into irb it works perfectly.

Any ideas?

Farrel

As you can see if I execute the code myself it seems to work. If I
copy that same code into irb it works perfectly.

You're calling Array#rand (a private method Array defines), whereas
you want to call Kernel#rand. Replace rand with Kernel.rand and you
should be ok

Fred

That was it. Thanks for the tip. I didn't know Rails added in it's own
rand method into Array.

Farrel