# Command-line implementation of Mastermind

I just finished this command-line implementation of the Mastermind board game that allows two players to play against each other. I'm fairly new to Ruby, but I think I did a decent job with this. However, I'm sure there are some things I could've done better, so please let me know if there are.

class Codebreaker
attr_accessor :colors

def initialize
@colors = []
end
end

require 'io/console'

class Codemaker
attr_accessor :code_colors

def make_code
puts "\nCodemaker, select 4 colors! Please enter them separated by spaces, with no commas.  To prevent cheating, your input will be hidden.  Try to not make any typos :)"
input = STDIN.noecho(&:gets).chomp
@code_colors = input.split(" ")
puts "Excellent!"
end
end

class Game
require_relative "codebreaker.rb"
require_relative "codemaker.rb"

def initialize
@code_breaker = Codebreaker.new
@code_maker = Codemaker.new
@turn = 1
start_game
end

def start_game
puts "Welcome to Mastermind!
\nRules:
\nThe codemaker creates a code consisting of four colors chosen from the provided list.
It is the goal of the codebreaker to crack the code in 12 turns, entering the same exact colors in the same order.  To attempt to crack the code, simply
keep guessing.
\nYou may choose from the following colors: red, blue, green, yellow, orange, purple, white, and black."
@code_maker.make_code
turn
end

def turn
while @turn < 12
code_breaker_input
compare
@turn += 1
if @turn == 12
puts "Unfortunately, you didn't guess the codemaker's code in the allotted 12 turns.  Better luck next time!"
exit
end
end
end

def code_breaker_input
puts "\nCodebreaker, please make your selection! Enter colors in lowercase, separated by spaces, with no commas."
@code_breaker.colors = gets.chomp
end

def compare
b_colors = @code_breaker.colors.downcase.split(" ")
m_colors = @code_maker.code_colors
correct_indexes = []
correct_colors = []

b_colors.zip(m_colors).map { |a, b|
if a == b
correct_indexes << "X"
else correct_indexes << "O"       end
}

b_colors.each { |color|
m_colors.any? { |c_color|
correct_colors << color if c_color == color
}
}

puts correct_indexes.join(" ")
puts "Colors guessed correctly: #{correct_colors.join(", ")}"

#checks win condition
if correct_indexes.all? { |index| index == "X" }
puts "The codemaker cracked the code!"
exit
end
end
end

game = Game.new
$$$$


• 12 is a magic number in your code, you can move it to a constant.
• I think TURNS.times do |turn| ... is better than the while loop because you don't have to keep track of the counter.
• When you're passing a simple space (" ") to the method split you can just call split instead, without passing any argument.
• When the block has multiple lines it is a good practice to use do and end instead of brackets.
• I think you can use the select method and assign the result directly to the correct_colors variable.
• I think it would be better to call Game.new.start_game instead of Game.new, for me, it isn't intuitive that the game will begin just by instantiating the Game` class.