Tic-Tac-Toe

[rdrake]

Kinda messy code, but it works well. It's your basic tic-tac-toe game. Not much variation, just works the way it's suppost to.

code:

######################## ## Tic-Tac-Toe        ## ## Dec. 9/05          ## ######################## # Declare variables row_1  = [" ", " ", "1", " ", "|", " ", "2", " ", "|", " ", "3", " ", " "] row_2  = [" ", " ", "4", " ", "|", " ", "5", " ", "|", " ", "6", " ", " "] row_3  = [" ", " ", "7", " ", "|", " ", "8", " ", "|", " ", "9", " ", " "] line   = "------------" number = 1 piece  = "X" # Main program loop loop do   # Draw the board   row_1.each do |char|     putc char   end   puts "\n#{line}"   row_2.each do |char|     putc char   end   puts "\n#{line}"   row_3.each do |char|     putc char   end   # Get player input   puts "\nPlayer #{number}:  Where would you like to move? (1 - 9)\n"   move = gets.chomp.to_i   # Make sure they don't move over another piece   if move < 4 then     num = move * 4 - 2     puts num     if row_1[num] == "X" or row_1[num] == "O" then       puts "Can't move there!"       next;     end   elsif move > 3 and move < 7 then     num = move * 4 - 14     puts num     if row_2[num] == "X" or row_2[num] == "O" then       puts "Can't move there!"       next;     end   elsif move > 6 and move < 10 then     num = move * 4 - 26     puts num     if row_3[num] == "X" or row_3[num] == "O" then       puts "Can't move there!"       next;     end   end   # Place piece if all is well   if move == 1 then     row_1[2] = piece   elsif move == 2 then     row_1[6] = piece   elsif move == 3 then     row_1[10] = piece   elsif move == 4 then     row_2[2] = piece   elsif move == 5 then     row_2[6] = piece   elsif move == 6 then     row_2[10] = piece   elsif move == 7 then     row_3[2] = piece   elsif move == 8 then     row_3[6] = piece   elsif move == 9 then     row_3[10] = piece   end     # Check for a winner   if row_1[2] == "X" and row_1[6] == "X" and row_1[10] == "X" then     puts "Player #{number} wins!"     break;   elsif row_1[2] == "O" and row_1[6] == "O" and row_1[10] == "O" then     puts "Player #{number} wins!"     break;   elsif row_2[2] == "X" and row_2[6] == "X" and row_2[10] == "X" then     puts "Player #{number} wins!"     break;   elsif row_2[2] == "O" and row_2[6] == "O" and row_2[10] == "O" then     puts "Player #{number} wins!"     break;   elsif row_3[2] == "X" and row_3[6] == "X" and row_3[10] == "X" then     puts "Player #{number} wins!"     break;   elsif row_3[2] == "O" and row_3[6] == "O" and row_3[10] == "O" then     puts "Player #{number} wins!"     break;   ##########   elsif row_1[2] == "X" and row_2[2] == "X" and row_3[2] == "X" then     puts "Player #{number} wins!"     break;   elsif row_1[2] == "O" and row_2[2] == "O" and row_3[2] == "O" then     puts "Player #{number} wins!"     break;   elsif row_1[6] == "X" and row_2[6] == "X" and row_3[6] == "X" then     puts "Player #{number} wins!"     break;   elsif row_1[6] == "O" and row_2[6] == "O" and row_3[6] == "O" then     puts "Player #{number} wins!"     break;   elsif row_1[10] == "X" and row_2[10] == "X" and row_3[10] == "X" then     puts "Player #{number} wins!"     break;   elsif row_1[10] == "O" and row_2[10] == "O" and row_3[10] == "O" then     puts "Player #{number} wins!"     break;   ##########   elsif row_1[2] == "X" and row_2[6] == "X" and row_3[10] == "X" then     puts "Player #{number} wins!"     break;   elsif row_1[2] == "O" and row_2[6] == "O" and row_3[10] == "O" then     puts "Player #{number} wins!"     break;   elsif row_1[10] == "X" and row_2[6] == "X" and row_3[2] == "X" then     puts "Player #{number} wins!"     break;   elsif row_1[10] == "O" and row_2[6] == "O" and row_3[2] == "O" then     puts "Player #{number} wins!"     break;   elsif row_1[2] == "X" or row_1[2] == "O" and row_1[6] == "X" or row_1[6] == "O" and row_1[10] == "X" or row_1[10] == "O" and row_2[2] == "X" or row_2[2] == "O" and row_2[6] == "X" or row_2[6] == "O" and row_2[10] == "X" or row_2[10] == "O" and row_3[2] == "X" or row_3[2] == "O" and row_3[6] == "X" or row_3[6] == "O" and row_3[10] == "X" or row_3[10] == "O" then     puts "No winner."     break;   end     # Select next player   if number == 2 then     number = 1     piece = "X"   else     number = 2     piece = "O"   end end

If there's too many lines, I can put it in a file and attach it instead. Comments/suggestions are welcome.

[wtd]

Now, rewrite it with some thought to separating logic and display code.

[wtd]

Some simple things while you ponder that...

code:

# Draw the board   puts row_1.join   puts line   puts row_2.join   puts line   puts row_3.join

Replaces:

code:

# Draw the board   row_1.each do |char|     putc char   end   puts "\n#{line}"   row_2.each do |char|     putc char   end   puts "\n#{line}"   row_3.each do |char|     putc char   end

code:

# Place piece if all is well    if move == 1 then     row_1[2] = piece   elsif move == 2 then     row_1[6] = piece   elsif move == 3 then     row_1[10] = piece   elsif move == 4 then     row_2[2] = piece   elsif move == 5 then     row_2[6] = piece   elsif move == 6 then     row_2[10] = piece   elsif move == 7 then     row_3[2] = piece   elsif move == 8 then     row_3[6] = piece   elsif move == 9 then     row_3[10] = piece   end

Can be:

code:

index = 2 + (move - 1) * 4   case move      when 1 .. 3         row_1[index] = piece      when 4 .. 6         row_2[index] = piece      when 7 .. 9         row_3[index] = piece   end

[wtd]

It's worth noting that you don't need three separate "row" variables. You can easily have:

code:

rows = [[" ", " ", "1", " ", "|", " ", "2", " ", "|", " ", "3", " ", " "],         [" ", " ", "4", " ", "|", " ", "5", " ", "|", " ", "6", " ", " "],         [" ", " ", "7", " ", "|", " ", "8", " ", "|", " ", "9", " ", " "]]

[rdrake]

wtd wrote:

Now, rewrite it with some thought to separating logic and display code.

What exactly do you mean? Can you provide an example. I'm fairly new to Ruby still.

Here's a version with nicer classes instead of just random code.

code:

######################## ## Tic-Tac-Toe        ## ## Dec. 9/05          ## ######################## class TTTGame   def initialize     # Declare variables     @row_1  = [" ", " ", "1", " ", "|", " ", "2", " ", "|", " ", "3", " ", " "]     @row_2  = [" ", " ", "4", " ", "|", " ", "5", " ", "|", " ", "6", " ", " "]     @row_3  = [" ", " ", "7", " ", "|", " ", "8", " ", "|", " ", "9", " ", " "]     line   = "------------"     number = 1     piece  = "X"   end   def drawBoard     # Draw the board     puts @row_1.join     puts line     puts @row_2.join     puts line     puts @row_3.join   end   def isWinner   # Check for a winner     if @row_1[2] == "X" and @row_1[6] == "X" and @row_1[10] == "X" then       puts "Player #{number} wins!"       break;     elsif @row_1[2] == "O" and @row_1[6] == "O" and @row_1[10] == "O" then       puts "Player #{number} wins!"       break;     elsif @row_2[2] == "X" and @row_2[6] == "X" and @row_2[10] == "X" then       puts "Player #{number} wins!"       break;     elsif @row_2[2] == "O" and @row_2[6] == "O" and @row_2[10] == "O" then       puts "Player #{number} wins!"       break;     elsif @row_3[2] == "X" and @row_3[6] == "X" and @row_3[10] == "X" then       puts "Player #{number} wins!"       break;     elsif @row_3[2] == "O" and @row_3[6] == "O" and @row_3[10] == "O" then       puts "Player #{number} wins!"       break;     elsif @row_1[2] == "X" and @row_2[2] == "X" and @row_3[2] == "X" then       puts "Player #{number} wins!"       break;     elsif @row_1[2] == "O" and @row_2[2] == "O" and @row_3[2] == "O" then       puts "Player #{number} wins!"       break;     elsif @row_1[6] == "X" and @row_2[6] == "X" and @row_3[6] == "X" then       puts "Player #{number} wins!"       break;     elsif @row_1[6] == "O" and @row_2[6] == "O" and @row_3[6] == "O" then       puts "Player #{number} wins!"       break;     elsif @row_1[10] == "X" and @row_2[10] == "X" and @row_3[10] == "X" then       puts "Player #{number} wins!"       break;     elsif @row_1[10] == "O" and @row_2[10] == "O" and @row_3[10] == "O" then       puts "Player #{number} wins!"       break;     elsif @row_1[2] == "X" and @row_2[6] == "X" and @row_3[10] == "X" then       puts "Player #{number} wins!"       break;     elsif @row_1[2] == "O" and @row_2[6] == "O" and @row_3[10] == "O" then       puts "Player #{number} wins!"       break;     elsif @row_1[10] == "X" and @row_2[6] == "X" and @row_3[2] == "X" then       puts "Player #{number} wins!"       break;     elsif @row_1[10] == "O" and @row_2[6] == "O" and @row_3[2] == "O" then       puts "Player #{number} wins!"       break;     elsif @row_1[2] == "X" or @row_1[2] == "O" and @row_1[6] == "X" or @row_1[6] == "O" and @row_1[10] == "X" or @row_1[10] == "O" and @row_2[2] == "X" or @row_2[2] == "O" and @row_2[6] == "X" or @row_2[6] == "O" and @row_2[10] == "X" or @row_2[10] == "O" and @row_3[2] == "X" or @row_3[2] == "O" and @row_3[6] == "X" or @row_3[6] == "O" and @row_3[10] == "X" or @row_3[10] == "O" then       puts "No winner."       break;     end   end   def placePiece     # Get player input     puts "\nPlayer #{@number}:  Where would you like to move? (1 - 9)\n"     move = gets.chomp.to_i     # Make sure they don't move over another piece     if move < 4 then       num = move * 4 - 2       if @row_1[num] == "X" or @row_1[num] == "O" then         puts "Can't move there!"         next;       end     elsif move > 3 and move < 7 then       num = move * 4 - 14       if @row_2[num] == "X" or @row_2[num] == "O" then         puts "Can't move there!"         next;       end     elsif move > 6 and move < 10 then       num = move * 4 - 26       if @row_3[num] == "X" or @row_3[num] == "O" then         puts "Can't move there!"         next;       end     end     # Place piece     @index = @move * 4 - 2     case @move       when 1 .. 3           @row_1[index] = piece       when 4 .. 6           @index -= 12           @row_2[index] = piece       when 7 .. 9           @index -= 24           @row_3[index] = piece     end   end   def changeTurn     # Select next player     if @number == 2 then       @number = 1       @piece = "X"     else       @number = 2       @piece = "O"     end   end end # Main program loop loop do   game = TTTGame.new   game.drawBoard   game.placePiece   game.isWinner   game.changeTurn end

[wtd]

cartoon_shark wrote:

wtd wrote:

Now, rewrite it with some thought to separating logic and display code.

What exactly do you mean? Can you provide an example. I'm fairly new to Ruby still.

Thinking about tic-tac-toe, we have a 3x3 grid. We can easily represent that in Ruby as an array of three arrays. Elements in the array can have one of three values. The possibilities are X, O and Empty. They should all start off empty.

code:

X = 0 O = 1 EMPTY = nil board = Array.new(3) { Array.new(3) { EMPTY } }

Now, we'd want to print this. So, let's define a new method to do this. Except we'll make it a bit more general and just have this generate a string representation of the board.

code:

def board_to_s(board)    board.zip([0, 1, 2]).collect do |row, row_number|       row.zip([0, 1, 2]).collect do |square, square_number|          case square             when X then "X"             when O then "O"             else row_number * 3 + square_number + 1                       end       end.join("|")    end.join("-+-+-") end

Now when we want to print a board, we can write:

code:

puts board_to_s(board)

But that's pretty redundant, so let's turn Board into a class. The initialize method will do the setup for us. The to_s method will do the same as our board_to_s method.

code:

class Board    X = 0    O = 1    EMPTY = nil        def initialize       @board = Array.new(3) { Array.new(3) { EMPTY } }    end        def to_s       @board.zip([0, 1, 2]).collect do |row, row_number|          row.zip([0, 1, 2]).collect do |square, square_number|             case square                when X then "X"                when O then "O"                else row_number * 3 + square_number + 1                          end          end.join("|")       end.join("-+-+-")    end end

And now we can:

code:

puts Board.new

And get:

code:

1|2|3 -+-+- 4|5|6 -+-+- 7|8|9

This is possible because the puts method automatically calls the to_s method on an object, and the new method of the Board class creates a new Board object.