Ruby public/private/protected

ruby_public_private_protected_example.rb

class PublicPerson
  def initialize(name)
    @name = name
  end

  def say_name
    puts @name
  end

  def say_other_name(person)
    person.say_name
  end
end


class PrivatePerson
  def initialize(name)
    @name = name
  end

  def say_other_name(person)
    person.say_name
  end

  private

  def say_name
    puts @name
  end
end

class ProtectedPerson
  def initialize(name)
    @name = name
  end

  def say_other_name(person)
    person.say_name
  end

  protected

  def say_name
    puts @name
  end
end

public_person1 = PublicPerson.new("Alex")
public_person2 = PublicPerson.new("Kate")
public_person1.say_other_name(public_person2) # => "Kate"

private_person1 = PrivatePerson.new("Alex")
private_person2 = PrivatePerson.new("Kate")
private_person1.say_other_name(private_person2) # => NoMethodError: private method `say_name' called for #<PrivatePerson:0x007f908e2631f0 @name="Kate">

protected_person1 = ProtectedPerson.new("Alex")
protected_person2 = ProtectedPerson.new("Kate")
protected_person1.say_other_name(protected_person2) # => "Kate"