CS 115 Pre-Lab 12 Instructions

Deadline: Tu 4/21/2015 at 7 AM

Refer to the Week 14 reading or other resources as necessary to complete this assignment.

Classes and objects

  1. Enter the following code into the online Python 3 tutor: 
    class Rectangle:
    def __init__(self, L, W):
        self.set_length(L)
        self.set_width(W)

    def set_width(self, W):
        self.width = W

    def set_length(self, L):
        self.length = L

    def get_width(self):
        return self.width

    def get_length(self):
        return self.length

    def get_area(self):
        return self.get_length() * self.get_width()

# STOP HERE
# This code uses the Rectangle class
r1 = Rectangle(1, 2) # Statement 1
r2 = Rectangle(5, 6) # Statement 2
a1 = r1.get_area() # Statement 3
a2 = r2.get_area() # Statement 4
  2. Step through the code, stopping at the labeled comment (when the red arrow gets to line 23). Notice how the code above the comment sets up the definition of the Rectangle class and its methods. Answer Question 1 in your writeup.
  3. Step through the complete execution of Statement 1, stopping when the red arrow gets to line 24. Notice that the stacks on the right-hand side of the screen grow downward, so that the current function call and the newly created objects are always at the bottom.
  4. Answer Question 2 in your writeup.
  5. Step through the complete execution of Statement 2, and answer Question 3 in your writeup.
  6. Step through the complete execution of Statements 3 and 4, and answer Question 4 in your writeup.

Submit the pre-lab (due Tu at 7 AM)

Review your answers, and then click the Next button at the bottom of the Moodle quiz. Once you do that, you should see something similar to this:
Quiz attempt summary

Click the Submit all and finish button. You MUST do this so that your pre-lab can be graded! Once you have submitted your quiz, you should see something similar to this at the top of your Moodle window. The important part is that the State shows up as Finished.
Quiz confirmation