pwightman

1.9.3p194 :006 > u.errors[:title] = "can't be blank"
 => "can't be blank" 
1.9.3p194 :007 > u.errors.full_messages
 => ["Title can't be blank"] 
1.9.3p194 :008 > u.errors[:base] = "Please don't do that"
 => "Please don't do that" 
1.9.3p194 :009 > u.errors.full_messages
 => ["Title can't be blank", "Please don't do that"] 

pwightman

class CartesianProduct
  include Enumerable

  def initialize a, b
    @a = a
    @b = b
  end

  # Every method has an implied block that is sent into it, it does NOT need to be
  # specified as a parameter.

pwightman

# (a)
class Class
  def attr_accessor_with_history attr

    attr = attr.to_s

    attr_reader attr

    class_eval %Q{
      # Create a history method for the attribute

pwightman

class Dessert
  attr_accessor :name, :calories

  def initialize(name, calories)
    @name = name
    @calories = calories
  end

  def healthy?
    @calories < 200

pwightman

def combine_anagrams words
  # Kendal's idea. Passing a block to the constructor is how you tell
  # the hash what to do when a key is accessed that doesn't yet exist.
  hash = Hash.new do |h, key|
    h[key] = []
  end

  words.each do |word|
    # As the key, we want to use the lowercase sorted
    # for of the word, as anagrams will always have the

pwightman

class WrongNumberOfPlayersError < StandardError ; end
class NoSuchStrategyError < StandardError ; end

def rps_game_winner(game)
  raise WrongNumberOfPlayersError unless game.length == 2

  player1 = game[0]
  player2 = game[1]

  player1_play = player1[1]

pwightman

def palindrome? str
  str.downcase!
  # gsub stands for "global substitution" and replaces all occurrences
  # of the matching regex with the given string. Here, we want all "non-word"
  # characters to be removed from the string
  str.gsub! /[\W]/, ""
  # If the forward and backward versions are the same, it's a palindrome
  str == str.reverse
end