Lecture 9

1. Getters and Setters

   Which of the below is a getter method for the number of wheels?

   ----------------------------------
   ----------- Given ------------
   ----------------------------------
   class Car(object):
    def __init__(self, w, d):
    self.wheels = w
    self.doors = d
    self.color = ""
   ----------------------------------
   
   (A)    def get_wheels():
    return wheels
   
   (B)    def get_wheels():
    return self.wheels
   
   (C)    def get_wheels(self):
    return wheels
   
   (D)    def get_wheels(self):
    return self.wheels
   

   def get_wheels(): close

   def get_wheels(): close

   def get_wheels(self): close

   def get_wheels(self): check

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2. Subclass

   Whate line could replace ____blank____ to create a class that inherets from Animal in the code below?

   ____blank____
    def speak(self):
     print("ruff ruff")
   
   (line1) d = Dog(7)
   (line2) d.set_name("Ruffles")
   (line3) d.speak()
   

    class Dog(Animal):  check

    class Animal(Dog):  close

    class Dog(object)  close

   Check

With this definition of Dog, you run a program with line1, line2, and line3 above. What happens? Refer to the lecture slides for the code making up the “Animal” class.

 Error on (line1) because Dog does not have an \_\_init\_\_  close

 Uses the \_\_init\_\_ from Animal, but then an error (line2) because Dog does not have a set\_name method.  close

 Uses the \_\_init\_\_ and set\_name from Animal, but then an error (line3) because all methods must return something.  close

 Runs, creates a Dog object with age=7 and name="Ruffles", and prints "ruff ruff"  check

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