In other words, what are attr_reader & attr_writer for?

Well, attr_reader and attr_writer are connected in some way to private and public.

You use private and public for methods. So with private and public you can make methods accessible or not outside of the class.

With instance variables, you can make them accessible or not with attr_reader and attr_writer outside of the class.

Let’s use this example:

class Person
  def initialize(name)
    @name = name
  end
end

Let’s say you create one Person p1 = Person.new("John") With the above class there is no way to change the name John to anything else. You would need to create another Person object with different name. Sometimes that is what you want and by not using attr_reader and attr_writer you are achieving that.

Now let’s look at this:

class Person
  attr_reader :name
  attr_writer :name
  def initialize(name)
    @name = name
  end
end

Now we can change the name of our Person (p1.name = "Other Name") without creating another Person object.

OR, if you want you can use methods for reaching instance variables instead of attr_reader and attr_writer but that is not in Rubys style since it is more code Example:

class Person
  def initialize(name)
    @name = name
  end

  def name 
    @name
  end

  def name=(value)
    @name = value
  end
end

Yes please, I was coming here for the same thing. The section is about information hiding, and then suddenly you move over to the read/write/access ideas using symbols with no clear reason or explanation how it connects to the public and private methods that were being covered previously.

My confusion was caused because I created a instance of the class and tried to print and change the attributes, and I was able to do it successfully even with attr_reader and attr_writer commented out, and with no methods. I couldn’t understand why we needed them at all. But when I opened my text editor and pasted the code and ran it using Ruby on my own computer, it didn’t work without attr_reader and attr_writer. So I think there is a problem with Codecademy’s implementation here.

OK so if I get this right all instance variables in Ruby are private by default and there is no public modifier for variables ?? The only way to make an instance variable accessible outside of the instance is by public method ?