C++ Exam Question Please Help

SharpshooterTom

Hi all,

I have a C++ exam on monday and I would appreciate some help. I'm currently going through some past papers and I need help on this question:

Design a C++ class to represent an object that consists of two

members, a and b. Provide methods to overload the assignment (=),
addition +, subtraction - , and division / operators, as given below.
Provide a constructor that can initialise the object with specified

values for a and b.

Operations on the object consisting of the members a and b with

another object with members c and d.

Addition: (a,b) + (c,d) = (a+c, b+d)
Subtraction (a,b)– (c,d) = (a-c, b-d)
Multiplication: (a,b)(c,d) = (ac-bd,bc+ad)

Division: (a,b)/(c,d) = ((ac+bd)/(c

^2 + d^2), (bc-ad)/ (c^2 + d^2))

(You may recognise this as the behaviour of complex numbers.)

I am absolutely hopeless with C++. The only help I can find relevant appears to be this example tutorial on classes.

Based on that I have made a hopeless attempt below:

[FONT=BookmanOldStyle][SIZE=2]//vectors: overloading operators[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]#include <iostream>[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]using namespace std;[/SIZE][/FONT]
 
[FONT=BookmanOldStyle][SIZE=2]class CVector {[/SIZE]
[INDENT][SIZE=2]public:[/SIZE]
[/INDENT][/FONT]
[INDENT][FONT=BookmanOldStyle][SIZE=2]int x,y;[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]CVector () {};[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]CVector (int,int);[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]CVector operator + (CVector);[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]CVector operator - (CVector);[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]CVector operator * (CVector);[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]CVector operator / (CVector);[/SIZE][/FONT]
[/INDENT][FONT=BookmanOldStyle][SIZE=2]};[/SIZE][/FONT]
 
[FONT=BookmanOldStyle][SIZE=2]CVector::CVector (int a, int b){[/SIZE]
[INDENT][SIZE=2]x = a;[/SIZE]
[/INDENT][/FONT]
[INDENT][FONT=BookmanOldStyle][SIZE=2]y = b;[/SIZE][/FONT]
[/INDENT][FONT=BookmanOldStyle][SIZE=2]}[/SIZE][/FONT]
 
[FONT=BookmanOldStyle][SIZE=2]CVector CVector::operator+ (CVector param) {[/SIZE]
[INDENT][SIZE=2]CVector temp;[/SIZE]
[/INDENT][/FONT]
[INDENT][FONT=BookmanOldStyle][SIZE=2]temp.x = x + param.x[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]temp.y = y + param.y;[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]return (temp);[/SIZE][/FONT]
[/INDENT][FONT=BookmanOldStyle][SIZE=2]}[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]CVector CVector::operator- (CVector param) {[/SIZE]
[INDENT][SIZE=2]CVector temp;[/SIZE]
[/INDENT][/FONT]
[INDENT][FONT=BookmanOldStyle][SIZE=2]temp.x = x - param.x[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]temp.y = y - param.y;[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]return (temp);[/SIZE][/FONT]
[/INDENT][FONT=BookmanOldStyle][SIZE=2]}[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2][SIZE=2]CVector CVector::operator* (CVector param) {[/SIZE]
[INDENT][SIZE=2]CVector temp;[/SIZE]
[/INDENT][/SIZE][/FONT][SIZE=2]
[INDENT][FONT=BookmanOldStyle][SIZE=2]temp.x = (x*param.x) + (y*param.y);[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]temp.y = (x*param.y) + (y*param.x);[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]return (temp);[/SIZE][/FONT]
[/INDENT][FONT=BookmanOldStyle]}[/FONT]
 
[FONT=BookmanOldStyle][SIZE=2]CVector CVector::operator* (CVector param) {[/SIZE]
[INDENT][SIZE=2]CVector temp;[/SIZE]
[/INDENT][/FONT]
[INDENT][FONT=BookmanOldStyle][SIZE=2]temp.x = (x*param.x) + (y*param.y)/((param.x)*(param.x) + (param.y)*(param.y));[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]temp.y = (y*param.x) + (x*param.y)/((param.x)*(param.x) + (param.y)*(param.y));[/SIZE][/FONT]
[FONT=BookmanOldStyle][SIZE=2]return (temp);[/SIZE][/FONT]
[/INDENT][FONT=BookmanOldStyle]}[/FONT]
 
[/SIZE]

I have no idea if this is right and I have no idea how to complete it. I'm unsure in the example I listed to include a b c d instead of actual numbers in the main function and if that would actually work.

Appreciate any help on how to start/complete it.

jgh_

http://courses.cms.caltech.edu/cs11/material/cpp/donnie/cpp-ops.html

Additionally you overloaded `*` twice (I think the second one you intended to overload `/` )

Also it says to overload the assignment operator, but never actually says what you're supposed to do with that... I recommend overloading it to print out a birthday cake.

Also your overloaded operator methods should look more like

const CVector operator+ ( const CVector& param ) { ... }