I have this class:
class Game
attr_accessor :player_fleet, :opponent_fleet
@player_fleet = []
@opponent_fleet = []
...
end
and create an instance like this:
my_game = Game.new
then use it like this:
my_game.opponent_fleet << opponent
which gives me this error:
undefined method `<<' for nil:NilClass (NoMethodError)
Why can't I treat an array like this? Do I have to create a method to push objects into the array?
You initialize @opponent_fleet at class level, so it's an instance variable of the class, not of the generated objects. Remember that in Ruby, even classes are objects :)
irb(main):001:0> class Game
irb(main):002:1> @foo = 3
irb(main):003:1> end
irb(main):004:0> Game.instance_eval { @foo }
=> 3
irb(main):005:0> Game.new.instance_eval { @foo }
=> nil
You want to initialize it in a constructor instead:
class Game
attr_accessor :player_fleet, :opponent_fleet
def initialize
@player_fleet = []
@opponent_fleet = []
end
end
