Held: Tuesday, 28 January 2014

Back to Outline 05 - Classes and Objects. On to Outline 07 - Some Basic Types: Numbers and Strings in Java.

Summary

We consider the design of arrays as an ADT and then the specifics of arrays in Java.

Related Pages

• Reading: Arrays
• Lab: Arrays
• Javadoc: java.util.ArrayList
• Javadoc: java.util.Arrays
• EBoard 6 (Source 6) (HTML 6) (PDF 6)

Overview

• ADT Design.
• Minimalist vs. maximalist design.
• Arrays.

Administrivia

• I may be late to class as I'm transporting children to school.
• Christine and Hannah want to talk to you about the TC corps.
• Sorry for not mentioning last night's mentor session. We'll have them every Monday night.
• Today's writeup: problems 1 and 6.
  • Due Friday
  • Subject: CSC 207 Writeup 4: Arrays (YOUR NAME(S))
• Extra credit:
  • CS Extras, Thursday: Ushahidi, Android, and 207 by Spencer, Daniel, and Lea.
  • CS Table Friday: The ACM Code of Ethics.
  • Convo Feb. 5. (I'll give my "Why go to convo" lecture closer to the date.)

ADTs, Revisted

When you design an ADT, you should think about

• Philosophy
• Practica
• Procedures
• ...

One big conceptual issue: Are you a minimalist or a maximalist? (Do you put as little or as much as possible in your design?)

After designing, think about implementation.

Arrays in Java

• Arrays are both an ADT (in the sense that we can think about them as meeting some abstract goals that can be implemented in many ways) and a data structure (in the sense that we can also pay attention to their implementation.
• We'll potentially look a little bit at their design.

Minimalist vs. Maximalist ADT Design

• What arguments do you have for "just as many procedures as you need, but no more"?
• What arguments do you have for "about as many procedures as you think that someone will use"?
• In coming up with your answers, you may want to consider the issue from the perspective of the client programmer and the implementing programmer.

Arrays, Revisited

• Suppose you had a maximalist view of ADT design. What other methods would you want arrays to support? (And yes, you can draw upon your experience with other languages.)
• We've talked a little bit about Java's basic array mechanism and you've even used them. What questions do you have?
• What different design decisions could we have made (other than simple minimalist/maximalist choices)? Some of mine include:
  • Static or dynamic?
  • Syntax: Special or standard?
  • ...
• We'll take a quick look at Java's Vector class, which follows the same indexed collection of homogenous values array except that
  • Vectors are dynamically sized
  • Vectors are objects, so their methods use standard call syntax
  • Vectors use more of a maximalist approach