00-recap.rb

# RECAP
# On representation:
# 1. The name of a dog.
# String
# Delimited by "" or ''
# 2. The age of a person.
# Integer
# 23
# 3. The height of a person in meters.
# Float
# 1.65
# 4. Affirmation of negation.
# boolean
# true / false
# 5. Process
# methods

#              parameters
def greet_user(user_name, times)
  times.times do
    puts "Hello, #{user_name}!"
  end
end

#          arguments
greet_user("John", 5)

1-voting-age.rb

## Live-code: Interactive voting age program
age = gets.chomp.to_i

if age >= 18
  puts "You can vote!"
else
  puts "You cannot vote!"
end

## Truthy
## Everything counts as true, except nil and false.
if true
  puts "true -> Yes"
end

if false
  puts "false -> No"
end

if nil
  puts "nil -> No"
end

if ''
  puts "'' -> Yes"
end

if 0
  puts "0 -> Yes"
end

if []
  puts "[] -> Yes"
end


## Using inline conditionals
puts "It prints" if true

## Unless (reverse of if)
age = gets.chomp.to_i

unless age >= 18
  puts "You cannot vote"
end

2-coin-flipper.rb

# Live-code: Let's flip coins

puts "Pick heads or tails"
user_guess = gets.chomp

result = ["heads", "tails"].sample # "heads" / "tails"

if result == user_guess
  puts "You win!"
else
  puts "You lost!"
end

# Can we make it shorter? Yes!
# Ternary operator
#     ..    .      ..        .      ..
# condition ? true statement : false statement
puts result == user_guess ? "You win!" : "You lose!"

3-morning-afternoon-night.rb

# Live-code: Morning? Afternoon? Evening? Lunch time!
hour = gets.chomp.to_i

# Say to which fraction of the day the hour belongs.
if hour < 12
  puts "Morning"
elsif hour > 18
  puts "Evening"
elsif hour > 12
  puts "Afternoon"
else
  puts "Lunch time!"
end

4-old-school-ui.rb

# Live-code: Old School UI

puts "You can (type it below):"
puts "- read"
puts "- write"
puts "- exit"
user_input = gets.chomp

# A bit repetitive on the comparisons
if user_input == "read"
  puts "TODO: reading"
elsif user_input == "write"
  puts "TODO: writing"
elsif user_input == "exit"
  puts "TODO: exiting"
else
  puts "Not valid."
end

# case makes it cleaner
case user_input
when "read"
  puts "TODO: reading"
when "write"
  puts "TODO: writing"
when "exit"
  puts "TODO: exiting"
else
  puts "Not valid."
end

# You can inline cases with then
case user_input
when "read"  then puts "TODO: reading"
when "write" then puts "TODO: writing"
when "exit"  then puts "TODO: exiting"
else
  puts "Not valid."
end

5-opening-hours.rb

# Live-code: Opening hours
# Print the state of a shop that opens at 8,
# closes at 19, but is closed at 12
puts "At what time?"
hour = gets.chomp.to_i

## A bit repetitive, but it works
if hour >= 8 && hour < 12
  puts "It's open!"
elsif hour > 12 && hour < 19
  puts "It's open!"
else
  puts "It's closed!"
end

## With || (or)
if (hour >= 8 && hour < 12) || (hour > 12 && hour < 19)
  puts "It's open!"
else
  puts "It's closed!"
end

6-the-right-price.rb

# Live-code: Find the right random number
number_to_find = rand(1..5)
# Give user the option to guess the number
# Print the result of the guess.
puts "Which number was it?"
user_guess = gets.chomp.to_i

# Option with while
while number_to_find != user_guess
  puts "Try again!"
  user_guess = gets.chomp.to_i
end

# Option with until (preferable)
until number_to_find == user_guess
  puts "Try again!"
  user_guess = gets.chomp.to_i
end

puts "You win!"

7-arrays.rb

# Declare an array of the main
# Dungeons and Dragons Cartoon characters

#               Index
#               0       1        2        3
characters = ["Bob", "Sheila", "Hank", "Erik"]
p characters
p characters.sort

# CRUD
# Create: Add an element
# characters.push("Uni") # same as below
characters << "Uni" # Shovel operator / push
p characters

# Read:
p characters[1]

# Update:
p characters[2] # => Hank
characters[2] = "Diana"
p characters[2] # => Diana

# Delete:
p characters
characters.delete_at(3)
p characters

8-iterations.rb

characters = ["Bob", "Sheila", "Uni"]
p characters

# do |character|
# end
characters.each do |character|
  puts character
end

## Runs once for each element in characters
## Everytime the element will be called character
for character in characters
  puts character # "Bob" / "Sheila" / "Hank" / "Erik"
end

## Iterating with while
characters_count = characters.count
iteration_count = 0
until iteration_count >= characters_count
  puts characters[iteration_count]
  iteration_count += 1
end