From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2010-03-30T00:26:56+09:00
Subject: Re: Another noob question

On Mon, Mar 29, 2010 at 4:55 PM, Omar Velez <dr_omar_velez@hotmail.com> wrote:
> Thanks to everyone that helped me a few days ago.  This time I am trying
> to write a program that incorporates everything that I have learned in
> the last week but I am more than sure that I am making mistakes
> somewhere.  Also there is somethings I do not know how to do.
> Everything is commented so it should be easy to find.  Also if anyone
> has any suggestions about my syntax style please give me advice.  Thanks
> again everyone!
>
> _______________________________________
>
> # Program written by Dr. Omar Israel Velez
>
> # This program will try to integrate several concepts that I have
> learned so far
> #  The program will ask for some basic information and then it will ask
> for a
> # list of favorite books.  Afterwards it will sum up the total number of
> # characters in the book titles and add how many of each letter there
> are.
> # finally it will offer a new book as a suggestion based on which letter
> was the
> # most popular.
>
> puts "What\s your first name?" ; first_name = gets.chomp ; puts
> puts "What\'s your last name?" ; last_name = gets.chomp ; puts
>
> puts "Well, #{first_name} #{last_name}, tell me four books that you have
> read:"
> puts

# > books_one = gets.chomp ; books_two = gets.chomp
# > books_three = gets.chomp ; books_four = gets.chomp
# > all_books = ["#{books_one.downcase}", "#{books_two.downcase}",
# > "#{books_three.downcase}", "#{books_four.downcase}"].sort

all_books = []
4.times do
   all_books << gets.chomp.downcase
end

all_books.sort!

>
> # Is there a more efficient way to write this code where I don't have to
> # isolate each one and I can downcase everything at once?
>
> puts
>
> puts "These are the books that you entered #{first_name}." ; puts

# > all_books.each do |books|
# >  puts books
# > end

puts books

>
> puts
>
> puts "#{first_name} are these books correct?" ; answer = gets.chomp ;
> puts
>
> if answer == 'yes'
>  puts "Ah, very good choice of books #{first_name}."
> else
>  puts "Well computers never make mistakes so it must be in your head."
>  puts "Run the program again please."

     exit

> end
>
> puts
>
# > a = books_one.length ; b = books_two.length
# > c = books_three.length ; d = books_four.length
> #  Same question as before, can I .length everything at the same time
> and make
> #  the code more efficient?
>
# > total_characters = a + b + c + d

total_characters = all_books.inject(0) {|total, book| total + book.length}

>
> #  I cheated and just went with the total number of characters.  But how
> do I
> #  add up the total number of each letter and then suggest a book for
> each letter?
> #  just two or three examples will be ok I know asking for 26 examples
> is just crazy.

# The letter histogram
h = Hash.new(0)
all_books.each {|b| b.split(//).each {|letter| h[letter] += 1}}

If you want to suggest a book for each letter, you'll have to have a
list of books by letter. Something like:

recommendations = {'a' => "A whatever", 'b' => "because..."} # Crazy !
I didn't come up with any book title !!!! (I'm not a native speaker)

Then you can recommend based on the present letters, if I understood correctly:

h.keys.each {|initial| puts "I recommend: #{recommendations[initial]}"}

> puts "There are #{total_characters} total characters in the tittles you
> read."
> puts
>
> if total_characters >= 50
>  puts "I recommend reading The Hobbit."
>  puts "There is a #{rand(101)}% chance you will like this book."
>  puts "Would you like to read this book?" ; answer = gets.chomp ; puts
>  if answer == 'yes'
>    puts "I am sure that you will enjoy it #{first_name}"
>  else
>    puts "Oh that is too bad, how about Animal Farm then?"
>    puts "There is a #{rand(101)}% chance you will like this book."
>  end
> else
>  puts "I recommend you read The Tale of Two Cities."
>  puts "There is a #{rand(101)}% chance you will like this book."
>  puts "Would you like to read this book #{first_name}?" ; answer =
> gets.chomp
>  puts
>  if answer == 'yes'
>    puts "I am sure that you will have a great time reading it!"
>  else
>    puts "Ok then, how about A Day in the Life of Alex Jones?"
>     puts "There is a #{rand(101)}% chance you will like this book."
>  end
> end

Whenever you see duplicated code, that's a good place to refactor:

def recommend(name, books)
  books.each do |book|
     puts "I recommend you read #{book}"
     puts "There's a #{rand(101)}% chance you'll like it"
     puts "Would you like to read this book #{name}?"
     answer = gets.chomp
     if answer == "yes"
       puts "I'm sure you'll like it"
       break
     end
  end
end

or something like that, then:

if total_characters < 50
   recommend(first_name, ["The Hobbit", "Animal Farm"])
else
   recommend(first_name, ["The Tale of Two Cities", "A Day in the Life
of Alex Jones"])
end

Well, this is not exactly equivalent to your code, but you get the idea.

>
> #  I also tried to create a global constant like so..
> #  percent =  "There is a #{rand(101)}% chance you will like this book."
> #  and then point to it to make the code look cleaner but it would not
> let me.
> #  How would I do this?

What didn't work?

percent = "There is a #{rand(101)} chance you'll like it"
puts percent

works for me. If you mean that it's always the same percentage, then
make it a method:

def percentage_sentence
  "There is a #{rand(101)} chance you'll like it"
end

puts percent

Jesus.