` Lecture 2

CS 151 - Lecture 4

Cover page image

Cay S. Horstmann

Lecture 4 Clicker Question 1

Go to Piazza and answer the question.

Which of the following best represents the relationship between classes User and Mailbox in homework 2A?

  1. What homework???

Lab

Clicker Questions

You just had a “clicker” question. There are several choices. Each student makes a choice. At the end, one can see which choices got how many votes, and the professor can see who made each choice.

Here, we used Piazza to gather the results. In some courses, you may have used a hardware device called a “clicker” for the same purpose.

Now imagine we would want to use cell phones instead. You will carry out the design discovery process that is described in chapter 2.

Functional Description

Discover Classes

On a whiteboard, write up the classes that your team thinks will be needed to implement the phone clicker system.

One of you takes a photo, shares it with everyone, and everyone adds it to their lab4 directory. Or if it's simpler, you can each take your own photo...

Don't erase the whiteboard. We'll discuss your work with the class after the lab is done.

Discover Responsibilities and Collaborators

Make CRC cards of the classes that you think you need. Provide responsibilities and collaborators.

Don't hesitate to tear up cards when you aren't happy with them.

Try playing a couple of scenarios. Which objects do what? Touch the cards and point to the responsibility that will make each step happen.

When you are done, everyone adds a photo of the index cards to their lab4 directory.

UML Diagram

On a whiteboard, draw a UML class diagram of all the classes that you have discovered. Take a photo and add it to the lab4 directory...

Don't erase the whiteboard...