In Ruby, how to write code inside a class so that getter foo and setter self.foo = … look more similar?

Question

In Ruby, inside a class\'s instance method, we use a getter by

foo

and we use a setter by

self.foo = something

Answer 1

Since local scope takes precedence, when you say foo = something, a local variable foo will be created and assigned the contents of something.

The reason you can write foo in order to use the getter is because Ruby will move up in scope when it can't find a variable with that name and it will eventually find the method.

If there is a local variable with the same name as the getter method, Ruby will use its value instead:

class Foo

  attr_accessor :foo

  def initialize
    @foo = :one
  end

  def f
    foo = :two
    foo
  end
end

Foo.new.f
# => :two

In order to make it clear that you want to access the setter, you must write self.foo = something. That will tell Ruby you want to execute the foo= method on the self object with something as parameter.