example.rb

def possible_win_combo(board, combos)
  combos.each do |combo|
    multiple_x = board.select {|space,value| combo.include?(space) && value == 'X'}
    if multiple_x.length == 2 
      return combo if (board[combo[0]] != 'O' && board[combo[1]] != 'O' && board[combo[2]] != 'O')
    end
  end
  nil #return not necessary, implicit
end

def possible_win_combo(board, combos)
  win_combo = nil
  combos.each do |combo|
    multiple_x = board.select {|space,value| combo.include?(space) && value == 'X'}
    if multiple_x.length == 2 
      win_combo = combo if (board[combo[0]] != 'O' && board[combo[1]] != 'O' && board[combo[2]] != 'O')
      break
    end
  end
  
  return win_combo
end