Total newbie: Instance variables in ruby?

Question

Pardon the total newbiew question but why is @game_score always nil?

#bowling.rb

class Bowling
  @game_score = 0
    def hit(pins)
        @game_score = @ga         


        

Answer 1

@game_score defined there is called class instance variable, which is a variable defined for the singleton class object:

class << Bowling
  attr_accessor :game_score
end

Bowling.game_score #=> 0

This is as you can tell different from the normal instance variables defined for instance objects.