Study System

Student Registration Example Ralph E. Johnson This document is a chapter from a textbook that is supposed to use patterns to teach introductory programming. The textbook will use Java, and is supposed to teach good style and good design from the beginning. Patterns are not the purpose of the book, but are a means to the end. The purpose of the book is to teach programming. Since these patterns are the first one that students learn, they are “elementary programs”. This chapter does not describe the patterns, but uses them as if they were described elsewhere in the book. Most of the patterns are described in the paper “Some Patterns of Novice Programs” by E. Wallingford, D. Steinberg, R. Duvall, R. Johnson, which is another PloP paper. It should probably be read before this one. In practice, students will skip between them. In this document, pattern names are underlined. This is partly because pattern names need to be easily distinguishable, and partly because the book is being developed on the web (at http://wiki.cs.uiuc.edu/ElementaryPatterns). The book is going to teach test-first programming and refactoring, but does not make a big deal about it. The goal is to make these techniques obvious and natural.

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Chapter 3 Representing information

One of the main uses of computers is to keep track of things. Computers keep track of everything you buy on a credit card, and print out your bill. They keep track of the phone calls you make on your cell phone. They keep track of the books in a library, and know when they have been checked out and where you should be able to find them. Your doctor's computer might keep track of your medical history. An engineer's computer might store the design of an automobile or a radio, and policemen are able to use computers that keep track of criminals. When you are designing an information system, it is helpful to separate the question "what does the system know?" from the question "what does the system do?" However, one of the...