Class 07: Lab: Objects and Classes, Revisited

Held Tuesday, September 5, 2000

Summary

Today you contniue to design your own classes.

Notes

• Due (by 5pm today):
  • Homework 1
  • How long did that assignment take you?
• Assigned:
  • Read Lab O1: Object-Oriented Design (for tomorrow)
  • Think about what classes you might use in a four-year planning system. (for tomorrow)
  • Homework 2 (due next Tuesday)
• I was sorry to see so few of you at yesterday's brown-bag lunch. It was actually quite interesting; there were videos of old GUI applications that seem more advanced than most things available today.
• I haven't had time to update the Linux handout. In the meanwhile, Ellie suggests that you might want to look at http://www.rochester.edu/ATS/UNIX/sysinfo/faq/problem/problem-index.html

Overview

• Design choices and output
• Lab J3, continued
  • Prepare
  • Work
  • Reflect

Design Choices and Output

• In object-oriented design (and in all program design) there are often many different ways to solve the same problem.
• In labs J2 and J3 you've seen at least three ways to print a point.
  • You can ask the point for information about itself and then use a SimpleOutput object to print that information.
  • You can hand the point a SimpleOutput object and ask the point to print itself.
  • You can hand both the point and the SimpleOutput object to a helper and ask the helper to print out the point.
• We'll spend a little while brainstorming about the advantages and disadvantages of each. We may ground our discussion in typical applications.
  • What if you want to print many different kinds of values?
  • What if you want to print points in different ways?
  • ...

Lab J3, Continued

Preparation

Any questions? Do you feel that you still need to do this lab after completing homework 1?

Work

Do the lab.

Reflect

What new things have you learned from this lab?