My method is outputting an entire array instead of an integer from within that array

Question

I am creating a tic tac toe game where I would like the computer to go in strategic spots based on the available winning combos on the board. For some reason, the computer_index method works until turn_count == 4, where it outputs the entire WIN_COMBINATIONS array instead of just one value. Understandably, this creates an error in the valid_move? method. The relevant error and code are as follows.

Traceback (most recent call last):
    3: from tictactoe.rb:12:in `<main>'
    2: from /Users/irosen419/Flatiron/code/tictactoe/tic_tac_toe.rb:201:in `play'
    1: from /Users/irosen419/Flatiron/code/tictactoe/tic_tac_toe.rb:117:in `comp_turn'
/Users/irosen419/Flatiron/code/tictactoe/tic_tac_toe.rb:40:in `valid_move?': undefined method `between?' for #<Array:0x00007fbe650d8268> (NoMethodError)

WIN_COMBINATIONS = [[0, 1, 2], [3, 4, 5], [6, 7, 8], [0, 4, 8], [2, 4, 6], [0, 3, 6], [1, 4, 7], [2, 5, 8]]

def valid_move?(index)
  index.between?(0,8) && !position_taken?(index)
end

def computer_index
  if turn_count == 0
    CORNERS.sample
  elsif turn_count == 2
    CORNERS.sample
  elsif turn_count == 4 || turn_count == 6
    WIN_COMBINATIONS.each do |combo|
      if @board[combo[0]] == "X" && @board[combo[1]] == "X"
          @board[combo[2]]
      elsif @board[combo[1]] == "X" && @board[combo[2]] == "X"
        @board[combo[0]]
      elsif @board[combo[0]] == "X" && @board[combo[2]] == "X"
        @board[combo[1]]
      elsif @board[combo[0]] == "O" && @board[combo[1]] == "O"
          @board[combo[2]]
      elsif @board[combo[1]] == "O" && @board[combo[2]] == "O"
        @board[combo[0]]
      elsif @board[combo[0]] == "O" && @board[combo[2]] == "O"
        @board[combo[1]]
      else
        CORNERS.sample
      end
    end
  else
    @board.each do |space|
      if space == " "
        space
      end
    end
  end
end

def comp_turn
  index = computer_index
  if valid_move?(index)
    move(index, current_player)
    display_board
  else
    comp_turn
  end
end

def turn_count
  count = 0
  @board.each do |space|
    if space == "X" || space == "O"
      count +=1
    end
  end
  count
end

Answer 1

I think you are missing return statements :

def computer_index
  if turn_count == 0
    CORNERS.sample
  elsif turn_count == 2
    CORNERS.sample
  elsif turn_count == 4 || turn_count == 6
    WIN_COMBINATIONS.each do |combo|
      if @board[combo[0]] == "X" && @board[combo[1]] == "X"
        return @board[combo[2]]
      elsif @board[combo[1]] == "X" && @board[combo[2]] == "X"
        return @board[combo[0]]
      elsif @board[combo[0]] == "X" && @board[combo[2]] == "X"
        return @board[combo[1]]
      elsif @board[combo[0]] == "O" && @board[combo[1]] == "O"
        return @board[combo[2]]
      elsif @board[combo[1]] == "O" && @board[combo[2]] == "O"
        return @board[combo[0]]
      elsif @board[combo[0]] == "O" && @board[combo[2]] == "O"
        return @board[combo[1]]
      else
        return CORNERS.sample
      end
    end
  else
    @board.each do |space|
      if space == " "
        space
      end
    end
  end
end