How can I make my tic-tac-toe game end in a tie?

Question

I have created a tic-tac-toe program in Ruby. I am having trouble with the part of the code which allows the game to end in a tie.

I wrote an if-statement to check for when a player wins the game. This is my else condition. When I try and run the program I get an error. What's wrong?

else 
  while @turn == "x" or "o"
    @square_count -= 1 # I set empty_count to 9 in the initialize of the class 
    # of this program. This would minus 1 from empty) count_each every turn
  end
  if @square_count == 0 #when all the slots are taken, its a tie game
    puts "Tie game!"
    return true  #this makes the program end
  end

The error I am getting is:

tac.rb:89: warning: string literal in condition
tac.rb:88:in `block in check_win': undefined method `-' for nil:NilClass (NoMethodError)
    from tac.rb:77:in `each'
    from tac.rb:77:in `check_win'
    from tac.rb:108:in `<class:Game>'
    from tac.rb:1:in `<main>'

Answer 1

Replace

while @turn == "x" or "o"

with

while @turn == "x" or @turn == "o"

Answer 2

It looks like @square_count might not be assigned a value, so you may be getting the error you indicate, as without an assignment, @square_count will hold a nil value.

Also, your while statement may not be what you want, the while statement will currently always evaluate as 'true' because of the value "o".