Reflection after my assessment 149

This is some code from my assessment. This is where I make a mistake. So I put it here as a reminder.

  class Dog
    attr_accessor :name
  end

  class Something
    def bob
      Dog.new 
    end
  end

  class Person < Something
    attr_accessor :name

    def initialize(n)
      @name = n
    end

    def Person.whatever;end

    def change_name(n)
      bob().name = n
    end
  end

  bob = Person.new('bob')
  bob.change_name('Robert')
  puts bob.name

The problem is in change_name, we call self.name , what if we call bob.name ? It dose not work, because bob is a local variable deifine on the outer area of the class. In ruby block is different from method, we can use outer variable in block, but we can not use outer variable directly in method. We have to pass into method as an arguement.

So bob.name can not work here. But if we inheritate from Something, there is a magic way happens to the bob. At first, I guesss it is some kine of variable(local variable, instance variable), but I forget there is a ., and Inheritance in ruby only pass methods to subclass. So bob. here, actually is bob(). the little dot is method invocation!!! we can not get variables to call. There is no variable then “dot” something.

They are some kind of easy but important mistakes that I make today:

1. local variable can not pass from outer area to inner area of method, unless you pass it by the arguement
2. dot is method invocation
3. You can pass methods from the superclass to the subclass in inheretence.