Contents

#--
# Credit goes to Niel Spring.
#++

class Array

  # As with #shuffle but modifies the array in place.
  # The algorithm used here is known as a Fisher-Yates shuffle.
  #
  #   require 'facet/array/shuffle'
  #
  #   a = [1,2,3,4]
  #   a.shuffle!
  #   a  #=> [2,4,1,3]
  #
  def shuffle!
    s = size
    each_index do |j|
      i = Kernel.rand(s-j)
      #self[j], self[j+i] = self[j+i], self[j]
      tmp = self[j]
      self[j] = self[j+i]
      self[j+i] = tmp
    end
    self
  end

end

Version data entries

3 entries across 3 versions & 1 rubygems

Version	Path
facets-0.7.0	lib/facet/array/shuffle%21.rb
facets-0.7.1	lib/facet/array/shuffle%21.rb
facets-0.7.2	lib/facet/array/shuffle%21.rb