无法访问ruby / rails中的类变量？

Question

I have a class like so:

Railsapp/lib/five9_providers/record_provider.rb:

class Five9Providers::RecordProvider < Five9Providers::BaseProvider

  def add_record_to_list
    variable = 'test'
  end

end

Then, in a controller I have this:

Railsapp/app/controllers/five9_controller.rb:

class Five9Controller < ApplicationController

    def import
      record_provider = Five9Providers::RecordProvider.new()
      record_provider.add_record_to_list
      puts Five9Providers::RecordProvider::variable
    end

end

However, calling my controller method import just returns:

NoMethodError (undefined method 'variable' for Five9Providers::RecordProvider:Class)

How can I access variable from the recover_provider.rb class in my five9_controller.rb class?

EDIT:

Even when using @@variable in both my record_provider and my five9_controller , I still can't access that variable. I am calling it like so: puts @@variable .

Answer 1

As written, you cannot. variable is local to the instance method and can't be accessed by any Ruby expression from outside the method.

On a related point, the term "class variable" is typically used to refer to variables of the form @@variable .

Update : In response to your "Edit" statement, if you change variable to @@variable in your class, then there are techniques available to access that variable from outside the class, but a naked reference to @@variable isn't one of them. Carefully read the answers to the question you cited in your comment for more information.

Answer 2

Best way is to set and get the value using methods. Below is a sample code

class Planet
  @@planets_count = 0

  def initialize(name)
    @name = name
    @@planets_count += 1
  end

  def self.planets_count
    @@planets_count
  end  

  def self.add_planet
    @@planets_count += 1
  end

  def add_planet_from_obj
    @@planets_count += 1
  end
end


Planet.new("uranus")
Plant.add_planet
obj = Planet.new("earth")
obj.add_planet_from_obj