Code snippet showing how to define private class methods in Ruby.

private_class_method_v3b.rb

class Toyota < Car
  def self.name
    self.i_am
  end

  def self.i_am
    "Toyota #{superclass}"
  end

  def self.do_something
    # I want to be private too
    puts "I'm private too! I do something."
  end
  
  # I added do_something to show that
  # private_class_method takes an array
  # of symbols corresponding to method
  # names.
  private_class_method :i_am, :do_something
end

# => Toyota.name
# "Toyota Car"
#
# => Toyota.i_am # expecting an error
# private method `i_am' called for Toyota:Class
#
# => Toyota.do_something # expecting an error
# private method `do_something' called for Toyota:Class