ruby-scripts

## RuBY

 remplazar s con th

print "Thtring, pleathe!: "
user_input = gets.chomp
user_input.downcase!

if user_input.include? "s"
  user_input.gsub!(/s/, "th")
else
  puts "Nothing to do here!"
end
  
puts "Your string is: #{user_input}"


## hash o diccionario

my_hash = { "name" => "Eric",
  "age" => 26,
  "hungry?" => true
}

puts my_hash["name"]
puts my_hash["age"]
puts my_hash["hungry?"]


## trabajando con diccionarios o hashes.

secret_identities = {
  "The Batman" => "Bruce Wayne",
  "Superman" => "Clark Kent",
  "Wonder Woman" => "Diana Prince",
  "Freakazoid" => "Dexter Douglas"
}
  
secret_identities.each do |item, name|
    puts "#{item}: #{name}"
end
lunch_order = {
  "Ryan" => "wonton soup",
  "Eric" => "hamburger",
  "Jimmy" => "sandwich",
  "Sasha" => "salad",
  "Cole" => "taco"
}

lunch_order.each {|element, food| puts "#{food}" }

### frecuencia de palabras.

puts "Introduzca sus palabras"
text = gets.chomp
words = text.split

frequencies = Hash.new(0)

words.each{ |word| frequencies[word] += 1 }
frequencies = frequencies.sort_by do |word, count|
    count
end
frequencies.reverse!
frequencies.each{|word, frequency| puts word + " " + frequency.to_s}


# method that capitalizes a word
def capitalize(string) 
  puts "#{string[0].upcase}#{string[1..-1]}"
end

capitalize("ryan") # prints "Ryan"
capitalize("jane") # prints "Jane"

# block that capitalizes each string in the array
["ryan", "jane"].each {|string| puts "#{string[0].upcase}#{string[1..-1]}"} # prints "Ryan", then "Jane"

= areglando en orden alfabetico decendente

fruits = ["orange", "apple", "banana", "pear", "grapes"]

fruits.sort! do |firstFruit, secondFruit|
  secondFruit <=> firstFruit
end



# benchmark


require 'benchmark'

string_AZ = Hash[("a".."z").to_a.zip((1..26).to_a)]
symbol_AZ = Hash[(:a..:z).to_a.zip((1..26).to_a)]

string_time = Benchmark.realtime do
  100_000.times { string_AZ["r"] }
end

symbol_time = Benchmark.realtime do
  100_000.times { symbol_AZ[:r] }
end

puts "String time: #{string_time} seconds."
puts "Symbol time: #{symbol_time} seconds."


## CRUD

movies = {
  Memento: 3,
  Primer: 4,
  Ishtar: 1
}

puts "What would you like to do?"
puts "-- Type 'add' to add a movie."
puts "-- Type 'update' to update a movie."
puts "-- Type 'display' to display all movies."
puts "-- Type 'delete' to delete a movie."

choice = gets.chomp.downcase
case choice
when 'add'
  puts "What movie do you want to add?"
  title = gets.chomp
  if movies[title.to_sym].nil?
    puts "What's the rating? (Type a number 0 to 4.)"
    rating = gets.chomp
    movies[title.to_sym] = rating.to_i
    puts "#{title} has been added with a rating of #{rating}."
  else
    puts "That movie already exists! Its rating is #{movies[title.to_sym]}."
  end
when 'update'
  puts "What movie do you want to update?"
  title = gets.chomp
  if movies[title.to_sym].nil?
    puts "Movie not found!"
  else
    puts "What's the new rating? (Type a number 0 to 4.)"
    rating = gets.chomp
    movies[title.to_sym] = rating.to_i
    puts "#{title} has been updated with new rating of #{rating}."
  end
when 'display'
  movies.each do |movie, rating|
    puts "#{movie}: #{rating}"
  end
when 'delete'
  puts "What movie do you want to delete?"
  title = gets.chomp
  if movies[title.to_sym].nil?
    puts "Movie not found!"
  else
    movies.delete(title.to_sym)
    puts "#{title} has been removed."
  end
else
  puts "Sorry, I didn't understand you."
end

## solo if

puts 1 < 2 ? "One is less than two!": "One is not less than two."

= IF

puts "What's your favorite language?"
language = gets.chomp

if language == "Ruby"
  puts "Ruby is great for web apps!"
elsif language == "Python"
  puts "Python is great for science."
elsif language == "JavaScript"
  puts "JavaScript makes websites awesome."
elsif language == "HTML"
  puts "HTML is what websites are made of!"
elsif language == "CSS"
  puts "CSS makes websites pretty."
else
  puts "I don't know that language!"
end

puts "What's your favorite language?"
language = gets.chomp

case language 
when "Ruby" then puts "Ruby is great for web apps!"
when "Python" then puts "Python is great for science."
when "JavaScript" then puts "JavaScript makes websites awesome."
when  "HTML" then puts "HTML is what websites are made of!"
when "CSS" then puts "CSS makes websites pretty."
else
  puts "I don't know that language!"
end


# codigo para imprimir un numero dado (n) de primos ruby 1.9. 

require 'prime'

def first_n_primes(n)
  # Check for correct input!
  "n must be an integer" unless n.is_a? Integer
  "n must be greater than 0" if n <= 0

  
  prime = Prime.instance
  prime.first n
end

first_n_primes(10)


# YIeld

def block_test
  puts "We're in the method!"
  puts "Yielding to the block..."
  yield # aca va el bloque. 
  puts "We're back in the method!"
end

block_test { puts ">>> We're in the block!" }