From: roob noob <lists@...>
Date: 2012-05-18T03:04:51+09:00
Subject: Re: what is going wrong here? The case of the noob not understanding initialize

Honestly I see very little difference between

"
message = "whatever"
encrypt(message) #returns the AES-256 encryption of message
"

and

"
@message
encrypt #returns the AES-256 encryption of @message
"

except that with an instance variable I can pass the value seamlessly to 
where it needs to go without sending it down the call chain and keeping 
track of a bunch of variables and changes to the variable.

  class AddNumbersAndLetters

    def get_input
      input = gets.chop
      add_numbers(input)
    end

     def add_numbers(input)
       numbers_added = input + "123"
       add_letters(numbers_added)
     end

     def add_letters(input)
        letters_added = input + "abc"
     end
  end

does not look as nice to me as

 class AddNumbersAndLetters

    def get_input
      @input = gets.chop
      add_numbers
      add_letters
    end

     def add_numbers
       @input += "123"
     end

     def add_letters
        @input += "abc"
     end
  end

especially if there are a lot more methods involved and I would 
otherwise need to keep passing input down the call chain with (), 
especially if I want to add numbers and then add letters and then add 
numbers again and then add letters again, which just becomes a mess 
passing with () but with @ it is as simply as doing this

add_numbers
add_letters
add_numbers
add_letters


However, enough Rubyists have told me to avoid using instance variables 
in this way that I will take your advice. I don't personally think it is 
the intuitive way to do things or that it makes it easier though.

-- 
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