KATHOLIEKE UNIVERSITEIT LEUVEN DEPT OF COMPUTER SCIENCE ESC

KATHOLIEKE UNIVERSITEIT LEUVEN DEPT. OF COMPUTER SCIENCE ESC Europe 1999 report Fundamentals of Class Design by Michel de Champlain 1

In general KATHOLIEKE UNIVERSITEIT LEUVEN DEPT. OF COMPUTER SCIENCE u Speaker w Michel de Champlain w Professor DECE Concordia University, Canada w Software Architect at Deep. Object. Knowledge ESC Europe 1999 report u Presentation w Basic w Focused on move from non-OO tot OO programming 2

Presentation Overview KATHOLIEKE UNIVERSITEIT LEUVEN DEPT. OF COMPUTER SCIENCE u explanation of principles of abstraction w evolution w pros/contras ESC Europe 1999 report u use of classes as abstraction mechanisms u guidelines/suggestions on using classes 3

Abstractions KATHOLIEKE UNIVERSITEIT LEUVEN ESC Europe 1999 report DEPT. OF COMPUTER SCIENCE u explanation of principles of abstractions w definition of abstraction w procedural abstraction vs data abstraction w definition of module S interface S implementation w CDS, ADS and ADT w ADS: if one instance is enough (mouse, keyboard) w ADT: if multiple instances exists (stack, window) 4

Classes and Objects KATHOLIEKE UNIVERSITEIT LEUVEN DEPT. OF COMPUTER SCIENCE u Classes as abstraction mechanisms ESC Europe 1999 report w definition of a class w definition of an object 5

Rules of Thumb KATHOLIEKE UNIVERSITEIT LEUVEN ESC Europe 1999 report DEPT. OF COMPUTER SCIENCE u Guidelines/suggestions on using classes w do not make fat classes w keep interfaces simple w only use a method when needed S not `by default` a getter/setter pair w methods should be S complete S minimal S foundational 6

Rules of Thumb KATHOLIEKE UNIVERSITEIT LEUVEN ESC Europe 1999 report DEPT. OF COMPUTER SCIENCE u Guidelines/suggestions on using classes w do not use large interfaces w `Special` methods S constructor S copy constructor S assignment S description (debugging) S equality S hash S print 7