anyone_can_learn_to_code_-_becoming_a_programmer

https://anyonecanlearntocode.com/tutorial/lessons/episode-1-intro-to-ruby

episode_1_intro_to_ruby.rb

#1
puts 3 - 6 #=> -3

#2
PUTS 3 + 3 #=> No Method Error

#3
p 7 + 3 #=> 10
puts 7 + 3 #=> 10
print 7 + 3 #=> 10

episode_2_code_flow_top_down.rb

#1
puts 8 #=> 8
puts 6 #=> 6
puts 7 #=> 7
puts 5 #=> 5
puts 3 #=> 3
puts 0 #=> 0
puts 9 #=> 9

#2
puts 3 #=> 3
puts 1 #=> 1
put 4 #=> No Method Error
puts 1 #=> 1
puts 5 #=> 5
puts 9 #=> 9

episode_3_code_flow_left_to_right.rb

#BODMAS

#1
puts 21 - 6 / 2 * 3 #=> 12

#2
puts 100 * 5 - 2 / 2 #=> 499
puts 100 * (5 - 2) / 2 #=> 150

#3
puts 1/0 #=> ZeroDivisionError: divided by 0

episode_4_strings.rb

#1
puts "Shegs " . "Olu"

episode_4a_things_that_can_go_wrong_with_strings.rb

#1
puts 12 * "4"					# should produce => 48
puts 12 * 4 #=> 48

puts 3 + " times a day"			# should produce => 3 times a day
puts "3" + " times a day" #=> 3 times a day

episode_5_intro_to_methods.rb

#1
puts "YUrI TOMoko".downcase

#2
puts "spaceship".reverse #=> pihsecaps
puts "racecar".reverse #=> racecar
puts 1776.reverse #=> 6771

#3
puts 12 * "4"					# should produce => 48
puts 12 * "4".to_i #=> 48

puts 3 + " times a day"			# should produce => 3 times a day
puts 3.to_s + " times a day" #=> 3 times a day			

episode_6_variables.rb

#1
a = 1
b = 2
c = a + b
d = c + a + b
puts d #=> 6

#2
hello = "goodnight"
world = " moon"
puts hello + world #=> goodnight moon
hello = cat
world = "fish"
puts hello + world #=> undefined local variable
x = 1
y = 2
puts x + y #=> 3

#3
a = 1
b = a
puts b #=> 1

#4
a = 1
b = a
a = 2
puts b #=> 1

episode_6a_things_that_can_go_wrong_with_variables.rb

#1
class Animal
  attr_accessor :name, :num_of_legs, :family

  def initialize(options)
    @name = options[:name]
    @num_of_legs = options[:num_of_legs]
    @family = options[:family]
  end

  def has_more_legs?(animal)
    num_of_legs > animal.num_of_legs
  end

  def creepy?
    num_of_legs > 4
  end

  def creepy_message
    creepy? ? "much creepy" : "much not creepy"
  end

  def description
    "This animal's name is #{name}. And the animal is very #{creepy_message}." \
      " It has #{num_of_legs} legs and is part of the #{family} family."
  end
end

xoloitzcuintli = Animal.new({name: "Xoloitzcuintli", num_of_legs: 4, family: "Canidae"})
ptarmigan = Animal.new({name: "Ptarmigan", num_of_legs: 2, family: "Phasianidae"})
tsetse_fly = Animal.new({name: "Tsetse Fly", num_of_legs: 6, family: "Glossinidae"})
platypus = Animal.new({name: "Platypus", num_of_legs: 4, family: "Ornithorhynchidae"})
assassin_bug = Animal.new({name: "Assassin Bug", num_of_legs: 6, family: "Assassin Bug"})
puts "Does the #{tsetse_fly.name} have more legs than #{ptarmigan.name}? : " + tsetse_fly.has_more_legs?(ptarmigan).to_s
puts "Is the #{xoloitzcuintli.name} creepy? : " + xoloitzcuintli.creepy?.to_s
puts platypus.description
puts assassin_bug.description
puts "Does the #{xoloitzcuintli.name} have more legs than #{tsetse_fly.name}? : " + xoloitzcuintli.has_more_legs?(tsetse_fly).to_s
puts tsetse_fly.description
puts xoloitzcuintli.description
puts "Is the #{platypus.name} creepy? : " + platypus.creepy?.to_s
puts ptarmigan.description

episode_7_more_about_variables.rb

#1
x = 3 #=> 3
x = x + 4 #=> 3 + 4 = 7
x = x - 5 #=> 7 - 5 = 2
puts x #=> 2
x = x + x #=> 2 + 2 = 4
x = x + x #=> 4 + 4 = 8
x = x + x #=> 8 + 8 = 16
x = x * x #=> 16 * 16 = 256
x = "goodbye" #=> goodbye

#2
first_number = 3
puts first_number + second_number #=> undefined local variable

#3
my_favorite_number = 9
your_favorite_number = 1
both = my_favorite_number + your_favorite_number
puts both #=> 10

episode_8_user_input.rb

#1
puts "Please, Enter first name: "
FIRST_NAME = gets.chomp

puts "Please, Enter middle name: "
MIDDLE_NAME = gets.chomp

puts "Please, Enter last name: "
LAST_NAME = gets.chomp

puts "Your full name is #{FIRST_NAME} #{MIDDLE_NAME} #{LAST_NAME}"

#2
SECONDS_IN_YEAR = 31556952

puts "How old are you: "

USR_AGE = gets.to_i

puts "You are #{SECONDS_IN_YEAR * USR_AGE} seconds old"

#3
print "Enter start year: "
START_YEAR = gets.to_i

print "Enter end year: "
END_YEAR = gets.to_i

print "#{END_YEAR - START_YEAR} years\n"

episode_8a_more_about_user_input.rb

#1
print "Please, Enter your name: "
USR_NAME = gets.chomp

print "Please, Enter your age: "
USR_AGE = gets.to_i

puts "Welcome #{USR_NAME}! In 10 years, you will be #{USR_AGE + 10}!"