Contents

class Array
  # Returns an unique array based on the criteria given as a +Proc+.
  #
  #   [1, 2, 3, 4].uniq_by { |i| i.odd? } # => [1, 2]
  #
  def uniq_by
    hash, array = {}, []
    each { |i| hash[yield(i)] ||= (array << i) }
    array
  end

  # Same as uniq_by, but modifies self.
  def uniq_by!
    replace(uniq_by{ |i| yield(i) })
  end
end

Version data entries

269 entries across 225 versions & 25 rubygems

Version	Path
activesupport-3.1.1.rc1	lib/active_support/core_ext/array/uniq_by.rb
activesupport-3.1.0	lib/active_support/core_ext/array/uniq_by.rb
activesupport-3.1.0.rc8	lib/active_support/core_ext/array/uniq_by.rb
activesupport-3.1.0.rc6	lib/active_support/core_ext/array/uniq_by.rb
activesupport-3.1.0.rc5	lib/active_support/core_ext/array/uniq_by.rb
activesupport-3.1.0.rc4	lib/active_support/core_ext/array/uniq_by.rb
activesupport-3.1.0.rc3	lib/active_support/core_ext/array/uniq_by.rb
activesupport-3.1.0.rc2	lib/active_support/core_ext/array/uniq_by.rb
activesupport-3.1.0.rc1	lib/active_support/core_ext/array/uniq_by.rb