J-Scag

# There once was a wise servant who saved the life of a prince. The king promised to pay whatever the servant could dream up. Knowing that the king loved chess, the servant told the king he would like to have grains of wheat. One grain on the first square of a chess board. Two grains on the next. Four on the third, and so on.

# There are 64 squares on a chessboard.

# Write a program that shows
# - how many grains were on each square, and
# - the total number of grains

# ## For bonus points

J-Scag

RSpec.configure do |config|
  # Use color in STDOUT
  config.color_enabled = true

  # Use color not only in STDOUT but also in pagers and files
  config.tty = true

  # Use the specified formatter
  config.formatter = :progress # :progress, :html, :textmate
end

J-Scag

def prime_slow?(number)
  (2..number/2).each {|num| return false if number % num == 0}
  true
end


puts prime_slow?(19)
puts prime_slow?(14)
puts prime_slow?(157)
puts prime_slow?(273)

J-Scag

filenames = [
  "foo-1.10.2.ext",
  "foo-1.11.ext",
  "foo-1.3.ext",
  "foo-1.50.ext",
  "foo-1.8.7.ext",
  "foo-1.9.3.ext",
  "foo-1.ext",
  "foo-10.1.ext",
  "foo-10.ext",

J-Scag

# Download this file:
# https://gist.github.com/aviflombaum/28534c5d69edd2439a7d/download

# Run it from your terminal with: 
# ruby ruby.basics.rb
# (Just make sure you are in the right directory)

# ======================================
# Ignore All This Code
# ======================================

J-Scag

# # Roman Numerals

# The Romans were a clever bunch. They conquered most of Europe and
# ruled it for hundreds of years. They invented concrete and straight
# roads and even bikinis. One thing they never discovered though was 
# the number zero. This made writing and dating extensive histories
# of their exploits slightly more challenging, but the system of
# numbers they came up with is still in use today. For example the
# BBC uses Roman numerals to date their programmes.

J-Scag

class Person

  def initialize(attribute_hash)
    @attr_hash = attribute_hash
    @attr_hash.each do |attribute, value|
      self.metaclass.send(:define_method, "#{attribute}") do
        @attr_hash[attribute]
      end
    end
  end

J-Scag

class Triangle

  attr_accessor :kind

  def initialize(a, b, c)
    raise TriangleError if a<=0 || b<=0 || c<=0
    raise TriangleError if a+b<=c || b+c<=a || a+c<=b
    if a == b && b == c
      self.kind = :equilateral
    elsif a == b || b == c || c == a

J-Scag

# A Jukebox filled with songs
# that responds to help, list, play, and exit
require_relative 'song'

class Jukebox
  attr_accessor :songs
  APPROVED_COMMANDS = [:list, :help, :exit]

  def initialize(songs)
    @songs = songs

J-Scag

class School

  attr_reader :name, :roster

  def initialize(name)
    @roster = {}
    @name = name
  end

  def add_student(name, grade)