CSC111 Exercises on Classes and Objects

--D. Thiebaut (talk) 13:05, 13 April 2014 (EDT)

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Exercise 1

class Bob:
   def __init__( self ):
        self._a = None

   def setA( self, x ):
        self._a = x

   def getA( self ):
       return self._a

Question 1

Create an object of type Bob, call it x, and set its member variable to 4

Question 2

Add 10 to the member variable of x.

Question 3

print the object contents of Object x. First by getting _a from x and printing it, then by adding a new method to Bob so that we can print objects just by passing them to print()

Exercise 2

This exercise is very similar to Exercise 1, but the definition of self._a is now self.a. Answer the same 3 questions.

Exercise 3

Go back to Bob containing a private member variable.

Question 1

Create 2 objects of type Bob, each containing the values 45 and 70, respectively, and save them in a list called L. Verify that the list contains these 2 objects.

Question 2

Change the value of the first element of the list to 10, and the value of the second one to 20. Verify that the change was made.

Question 3

Create 20 objects of type Bob, each containing 1, 2, 3,... 20, respectively, and save them in a list called L2. Display the contents of the list.

Question 4

Reset the values in all 20 objects in L2 to 0. Verify that the reset operation was successful.

Exercise 4

This exercise is very similar to Exercise 3, but we construct a new class that contains a list of objects of type Bob. Answer the same questions as in Exercise 3.