An instance method for Ruby's Array class which picks a number of elements from the array at random

array#pick.rb

class Array
  # Pick +number+ random elements out of the array. If +number+ is
  # greater than the size of the array, this method will simply return
  # the array itself, sorted randomly.
  
  def pick(number)
    sort_by { rand }.slice(0...number)
  end
end