Private methods in Ruby

Let’s start with the basic solution, that define all private methods under private and at the end of the class definition.

class Foo
  def bar
    :awesome
  end
​
  private
​
  def baz
    :something_private
  end
end

All methods under private are defined as private

We can define each individual method instead:

class Foo
  def bar
    :awesome
  end
​
  private def baz
    :something_private
  end
end

Note: By default, a class is public

We can always change the method properties after define them

class Example
 def xmethod
 end

 def ymethod
 end

 def zmethod 
 end

 private :xmethod, :zmethod

end

Same for a class attr:

class Foo
  private attr_accessor :awesome_variable
end

Sources:

• https://thecodest.co/blog/ruby-3-0-ruby-and-lesser-known-privacy-control-methods/
• https://stackoverflow.com/questions/10724221/where-to-place-private-methods-in-ruby
• http://ruby-for-beginners.rubymonstas.org/advanced/private_methods.html