My favorite Ruby Core Extensions.

core_ext.rb

class Object
  # Check to see if a the object exists within an array. This is a reflexion of
  # {Array#include?} to make conditionals more readable.
  #
  # @param array [Array(Object)] The array to check
  #
  # @example
  #   'Draper'.in? ['Sterling', 'Cooper', 'Draper', 'Pryce']
  #   # => true
  #
  # @example
  #   'Harris'.in? ['Sterling', 'Cooper', 'Draper', 'Pryce']
  #   # => false
  #
  def in?(array)
    array.include?(self)
  end
end #Object