Held: Wednesday, 10 September 2014

Back to Outline 07 - Classes and Objects, Revisited. On to Outline 09 - 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
• Javadoc: java.util.Vector
• EBoard 8 (Source 8) (HTML 8)

Overview

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

Administrivia

• New partners!
• Review session tomorrow at 11 am.
• Note: Mr. Walker and I approach this material very differently.
  • We have different stylistic guidelines. (E.g., use of this)
  • We prioritize different ideas.
• I will try to balance talking and lab today. Stop me at 11:20 so that you have time for lab.

Upcoming Work

• HW 4 assigned.
  • You can choose your own partners.
  • You can ask me to choose partners for you.
• Daily lab writeup: http://bit.ly/207writeup
• Readings for Friday:
  • Numeric Values in Java
  • Strings in Java
  • Input and Output in Java

Extra Credit Opportunities

Academic

• Convo TODAY at noon (immediately after class). "Limiting Armed Drone Proliferation" by Micah Zenko, the Douglas Dillon fellow in the Center for Preventive Action at the Council on Foreign Relations and vice chair of the World Economic Forum Global Agenda Council on Terrorism.
• Any other event in the Rosenfield Drones program.
• CS Extra, Thursday, September 11: Ajuna Kyaruzi '17 on being a SysAdmin
• CS Table, Friday, September 12: Socially-Assistive Robots Help Children with Autism

Peer Support

• ?

Miscellaneous

• Project IGNITE!
• Second-year students get extra credit for doing the second-year science retreat on Sept. 20.
• Second-year students also get extra credit for filling in the email survey.

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