meet it

Open a window onto your object's data.

Code outside a class cannot see @name. writes a little method called name that hands back @name. writes a reader and a writer, so outside code can also say pet.age = 4.

puts calls an object's to_s method to get its text. A new class shows something messy like #<Pet:0x...>, so write your own to_s that hands back a tidy string. Then puts pet and "#{pet}" both read nicely.

class Pet
  attr_accessor :name, :age
  def to_s
    "#{name}, aged #{age}"
  end
end
pet = Pet.new
pet.name = "Rex"
pet.age = 4
puts pet

Inside the class, name calls the reader, so you can write name instead of @name.

guess first

Reader or writer? What will this show?

Guess before you run it. Wrong guesses are how you learn, and nothing is marked.

class Book
  attr_reader :title
  def initialize(title)
    @title = title
  end
end
book = Book.new("Matilda")
puts book.title
book.title = "Holes"

your turn

Your turn. Rate a film.

Fill in a film title and a whole-number rating out of 5, then press run. puts film uses your to_s.

Your code

press run to see what happens

fix it

The football card shows nonsense. Can you fix it?

Broken code to fix

press run to see what happens

puts shows a strange code instead of the sentence. Which method does puts look for?
puts calls a method named to_s. Ruby has never heard of to_string.
Rename to_string to to_s on line 3, then press run.

nailed it

your objects can introduce themselves. :D

attr_reader lets outside code read a value.
attr_accessor lets it read and change the value.
Write to_s so puts shows your object nicely.

new words in your collection

attr_reader
attr_accessor

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