Question

I have a Card class and I want to overload the > operator to compare against another card (Ace is higher than king, king higher than queen, etc). I’ve forgotten what little I ever knew about Ruby and don’t have a clue where to start.

class Card
  @@RANKS = ['A', 'K', 'Q', 'J', 'T', '9', '8','7','6','5','4','3','2']
  attr_reader :rank

  def initialize(str)
    @rank = str[0,1]
  end

  def > (other)
    #?????
  end
end

Answer 1

You can use the array.index method. The following code checks the index of both cards and returns true if the other card appears after the current card.

class Card
  @@RANKS = ['A', 'K', 'Q', 'J', 'T', '9', '8','7','6','5','4','3','2']
  attr_reader :rank

  def initialize(str)
    @rank = str[0,1]
  end

  def > (other)
    @@RANKS.index(other.rank) > @@RANKS.index(@rank)
  end
end

ace = Card.new 'A'
king = Card.new 'K'
nine = Card.new '9'

puts ace > king
puts ace > nine
puts nine > king