Ruby 02 - Flow and Array

01-recap.rb

# Data Types / Built-in Objects

"Word" # String
'Word' # String

34 # Integer
3.14 # Float

true # Boolean - TrueClass
false # Boolean - FalseClass

nil # Nil

# Array
# puts obj.inspect
p [34, 3.14, true, "Hello"]

# Range
(1..10) # includes the last element
(1...10) # excludes the last element

# Variables (snake_case)
first_name = 'rui'
last_name = 'freitas'

# Concatenation
# (combining strings together)
puts first_name + " " + last_name

# Interpolation
# inject ruby expressions into strings
puts "#{first_name} #{last_name}"
puts '#{first_name} #{last_name}'

# Method

#              parameters
def full_name(first_name, last_name)
  # Guard clause:
  # return first_name.capitalize if first_name.length <= 4

  if first_name.length <= 4
    first_name.capitalize
  else
    "#{first_name.capitalize} #{last_name.capitalize}"
  end
end

#.             var defined in lines 23 and 24
#               arguments
puts full_name(first_name, last_name)
puts full_name("john", "doe")

02-flow.rb

# Pseudocode
# ask user for their age
# capture/store the age
# compare the age with 18
# if age is over 18 can vote

puts "What's your age?"
print "> "

age = gets.chomp.to_i

# If structure
# if age >= 18
#   puts "You can vote!"
# end


# Inline if/condition
# puts "You can vote!" if age >= 18

# Inline unless
# puts "You can vote!" unless age < 18

# If/Else Strucutre
if age >= 18
  # runs if true
  puts "You can vote!"
else
  # runs if false
  puts "Go home! You're a kiddo!"
end

03-coin_toss.rb

# Ask user to pick a side and store choice # gets.chomp
# Program should pick a random side Array#sample
# Compare user choice with coin

puts "Heads or tails?"
print "> "

choice = gets.chomp.downcase

# ['heads', 'tails']
coin = %w[heads tails].sample

# if choice == coin
#   puts "You win!"
# else
#   puts "You loose!"
# end


# Ternary operator
#           ? run if true  : run if false (else)
# condition ? do something : do something else
puts choice == coin ? "You win!" : "You loose!"

04-greeting.rb

# Good morning: before 12
# Good afternoon: after 13 until 18
# Good evening: after 18 until 20
# Good night: after 20

hour = Time.now.hour

if hour < 12
  puts "Good morning"
elsif hour >= 13 && hour <= 18
  puts "Good afternoon"
elsif hour > 18 && hour <= 20
  puts "Good evening"
elsif hour > 20
  puts "Good night"
else
  puts "Enjoy your lunch!"
end

05-interface.rb

puts "Which action? [ read | write | list | dance | exit ]"
print "> "

choice = gets.chomp.downcase.strip

case choice
when  "read"
  puts "Reading..."
when "write"
  puts "Writing..."
when "list"
  puts "Listing..."
when "dance"
  puts "Dancing..."
when "exit"
  puts "Goodbye!"
else
  puts "Unknown option!"
end

06-looping.rb

# puts "Guess the number (1-5)?"
# print "> "

# price_to_find = rand(1..5)

# choice = gets.chomp.to_i

# while choice != price_to_find
#   puts "Wrong number! Try again."
#   print "> "
#   choice = gets.chomp.to_i
# end

# until choice == price_to_find
#   puts "Wrong number! Try again."
#   print "> "
#   choice = gets.chomp.to_i
# end

# puts "You picked #{choice} and the number was #{price_to_find}"
# puts "Correct! You win!"


counter = 0
for num in ["a", "b", "c"]
  counter += 1
  print "Counter: #{counter}"
  puts num
end

07-arrays.rb

#            0        1       2.   # indexes
beatles = ["john", "ringo", "seb"]

puts beatles.size
puts beatles.length
puts beatles.count

# Read
puts beatles[1]

puts beatles[beatles.length - 1]
puts beatles.last

# Writing
p beatles
puts beatles[1] = "paul"
p beatles

# Append
beatles << "mike"
p beatles

# Prepending
beatles.unshift("susan")
p beatles

# Delete
# by value
beatles << "seb"
p beatles
# beatles.delete("seb")
# p beatles

# by index
beatles.delete_at(2)
p beatles

beatles.each do |beatle|
  puts "Hello #{beatle.capitalize}"
end