Question of the Week: What's Wrong With the following OO design?

djmightymike · 05-07-2007, 04:59 PM

class Engine {}
class Car : public Engine {}
class Boat : public Engine {}

Leave your comments

Chxta · 05-08-2007, 01:09 AM

I failed that course work.

maestro · 05-08-2007, 01:38 AM

Quote:

Originally Posted by chxta

I failed that course work.

rush3k · 05-08-2007, 05:56 AM

car is not an engine, boat is not an engine?

djmightymike · 05-08-2007, 04:25 PM

Quote:

Originally Posted by rush3k

car is not an engine, boat is not an engine?

very good

The is an example of a Is a vs has a Relationship
Both car and boat are not engines. They should instead have an engine as a component just like in the real world, thus the Psuedocode should have been written something like

#include Engine.h
Class Boat {
public
Boat {...} //constructor
Somefunctions {..} //some member functions
.
.
.
Protected:
Engine mEngine; //an instance of engine as a member of Boat

More Brain teasers coming

05-07-2007, 04:59 PM	#1 (permalink)
djmightymike Registered User Join Date: Dec 2006 Location: Festac Town Posts: 8,638 Points: 1,278,100,513.38 Bank: 0.02 Total Points: 1,278,100,513.40 Donate Rep Power: 21474865	Question of the Week: What's Wrong With the following OO design? class Engine {} class Car : public Engine {} class Boat : public Engine {} Leave your comments __________________ The Lord is my Shepherd -Psalms 23 http://djmightymike.net http://truspotradio.com http://myspace.com/naijadjs http://myspace.com/dj_mightymike

05-08-2007, 01:09 AM	#2 (permalink)
Chxta Registered User Join Date: Nov 2007 Location: 3rd rock from the Sun Posts: 8,541 Points: 9,667.30 Bank: 0.00 Total Points: 9,667.30 Donate Rep Power: 21474863	I failed that course work. __________________ I have never killed a man, but I have read many obituaries with great pleasure.

05-08-2007, 05:56 AM	#4 (permalink)
rush3k Registered User Join Date: Mar 2007 Posts: 111 Points: 807.85 Bank: 0.00 Total Points: 807.85 Donate Rep Power: 0	car is not an engine, boat is not an engine? __________________ The-All-Swearing-All-Drinking-Heavy-Metal Nigerian http://www.last.fm/user/rush3k/

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