what'ch think of my fraction program, is it correct and good and efficient?

J

John Cho

// CHO, JOHN

#include<iostream>


class fracpri{
int whole;
int numer;
int denom;

public:
// constructors:

fracpri();
fracpri(int w, int n, int d);
fracpri(float f); // float to class constructor

// member functions to show output and get input
void getFraction();
void showFraction();

// function and operators to do artimathetic
fracpri addfracts(fracpri &obj1, fracpri &obj2);
fracpri operator+(fracpri &obj2);
fracpri operator-(fracpri &obj2);
fracpri operator*(fracpri &obj2);
fracpri operator/(fracpri &obj2);

// adding with constants
friend fracpri operator +(int i, fracpri &obj2);
friend fracpri operator +(fracpri &obj1, int i);

// the compare operator, <
bool operator<(fracpri &obj2);

// the += operator
fracpri& operator+=(fracpri &obj2);

// overloading the input and output, >> and << operators.
friend std::istream& operator>> (std::istream& in, fracpri& obj2);
// std:: is used because
friend std::eek:stream& operator<< (std::eek:stream& out, fracpri const&
obj2);
// namespace std is after it


void reduce();

operator float(); // class to float conversion

};

using namespace std; // namespace needs to be after any use of
friend
// or else msvc++ 6.0 gives errors


fracpri::fracpri(){
whole = 0;
numer = 0;
denom = 1; // it is set as 1 so the adding fractions
works with a
// common denominator and not 0
}

fracpri::fracpri(int w, int n, int d){
whole = w;
numer = n;
denom = d;
if(denom == 0)
denom = 1;
reduce();
}

fracpri::fracpri(float f){ //float type to class type constructor

f += 0.0078125; // .0078125 so numerator is rounded up later
whole = int(f);
float flofrac = f - whole; // the fraction part of the number
numer = (flofrac * 64); // .0078125 * 64 = .5 ; so rounded up
numerator
// if orignal fraction
denom = 64;
reduce();
}

void fracpri::getFraction(){
char ch;
cout << "Enter a stock price in the form of " << endl;
cout << "wholenumber-numerator-denominator" << endl;
cin >> whole >> ch >> numer >> ch >> denom;
if(denom == 0)
denom = 1; // fix the denom if it is 0
reduce();
}

void fracpri::showFraction(){

cout << "The stock price is: " << endl;
cout << whole << ' ' << numer << '/' << denom << endl;

}





fracpri fracpri::addfracts(fracpri &obj1, fracpri &obj2){
whole = obj1.whole + obj2.whole;
numer = (obj1.numer * obj2.denom) + (obj2.numer * obj1.denom);
denom = obj1.denom * obj2.denom;

reduce();
return *this;
}

fracpri fracpri::eek:perator +(fracpri &obj2){
fracpri temp; // temp is here because *this would modify
// the first object or a in
// c = a + b
temp.whole = whole + obj2.whole;
temp.numer = (numer * obj2.denom) + (obj2.numer * denom);
temp.denom = denom * obj2.denom;

temp.reduce();
return temp;
}

fracpri fracpri::eek:perator -(fracpri &obj2){
fracpri temp;

// they are converted to improper fractions
// because the second fraction may be larger than the
// first and may cause the final fraction to be negative
// and the whole number to be positive

temp.whole = whole - obj2.whole;
temp.numer = ((whole * denom + numer)*obj2.denom) - ((obj2.whole *
obj2.denom + obj2.numer)*denom);
temp.denom = denom * obj2.denom;

temp.reduce();
return temp;
}

fracpri fracpri::eek:perator *(fracpri &obj2){
fracpri temp;

// convert both to improper
temp.numer = ((whole * denom) + numer) * ((obj2.whole * obj2.denom)
+ obj2.numer);

// the denominator is the two fractions denominators multiplied
together
temp.denom = denom * obj2.denom;

temp.whole = temp.numer/temp.denom;

temp.numer %= temp.denom;

temp.reduce();
return temp;
}
fracpri fracpri::eek:perator /(fracpri &obj2){
fracpri temp;


// convert both to improper
temp.numer = ((whole * denom) + numer) * obj2.denom;

temp.denom = denom * ((obj2.whole * obj2.denom) + obj2.numer);

temp.whole = temp.numer/temp.denom;

temp.numer %= temp.denom;

temp.reduce();

return temp;
}

fracpri operator+(int i, fracpri &obj2){
fracpri temp;

temp.whole = i + obj2.whole;
temp.numer = obj2.numer;
temp.denom = obj2.denom;


return temp;
}

fracpri operator+(fracpri &obj1, int i){
fracpri temp;

temp.whole = obj1.whole + i;
temp.numer = obj1.numer;
temp.denom = obj1.denom;


return temp;
}

bool fracpri::eek:perator<(fracpri &obj2){

// each fractions is multiplied by the other fraction's denominator
so that both fractions
// numerators are the result of a common denominator, which is denom
*obj2.denom
// each fraction's orignal denominator cancels out when the common
denominator is multiplied
// to each of the fractions.

if(((whole * denom + numer)*obj2.denom) < ((obj2.whole * obj2.denom
+ numer)* denom))
return true;
else
return false;
}

fracpri& fracpri::eek:perator +=(fracpri &obj2){
whole += obj2.whole; // same as whole = whole + obj2.whole
numer = (numer * obj2.denom) + (obj2.numer * denom);
denom *= obj2.denom; // same as denom = denom * obj2.denom

reduce();
return *this;
}

istream& operator >>(istream &in, fracpri &obj2){
char ch;
in >> obj2.whole >> ch >> obj2.numer >> ch >> obj2.denom;

if(obj2.denom == 0)
obj2.denom = 1;

obj2.reduce();
return in;
}

ostream& operator <<(ostream &out, fracpri const& obj2){
out << obj2.whole << ' ' << obj2.numer ;
out << '/' << obj2.denom;

return out;
}

fracpri::eek:perator float(){ // class type to float type

// float cast is needed because int divided by int results in int
and not float
// however float divided by int equals a float
float f = float(numer)/denom;

return f + whole;
}

void fracpri::reduce(){
while(numer >= denom){
whole++;
numer -= denom;
}
int count = numer * denom; // a common denominator
for(; count > 1; count--){
if((numer % count == 0) && (denom % count == 0)){ // if count fits
into both
numer /= count; // numerator and denominator without a
remainder,
denom /= count; // then divide both of them by that
// and then continue to count down
}
}
}



int main(){

int choice = 0; // used check if the calculations
should be reran
fracpri stock1; // a. 0 argument constructor
fracpri stock2(5,1,3); // b. 3 argument constructor
float decimal = 0.0;

fracpri stock[3];

do{
cout << "Enter two stock prices that will then be used" << endl;
cout << "with all the functions of this program" << endl;

cout << "Enter a stock price using getFraction" << endl;
stock[0].getFraction(); // c. getfraction function
cout << "Enter a stock price using >> operator" << endl;
cout << "In the form of whole-numerator-denominator" << endl;
cin >> stock[1]; // l. the >> operator

cout << "Using addfracts function and << operator" << endl;
stock[2].addfracts(stock[0], stock[1]); //e. addfracts
cout << stock[2] << endl;;

cout << "Using + operator, overloaded, and showFraction() function"
<< endl;
stock[2] = stock[0] + stock[1]; // f. + , -, *, and / overloaded
stock[2].showFraction();

cout << "Using - operator, overloaded, and << overloaded" << endl;
stock[2] = stock[0] - stock[1]; // f.
cout << stock[2] << endl;

cout << "Using * operator, overloaded, and << overloaded" << endl;
stock[2] = stock[0] * stock[1]; // f.
cout << stock[2] << endl;

cout << "Using / operator, overloaded, and showFraction() function"
<< endl;
stock[2] = stock[0] / stock[1]; // f.
stock[2].showFraction();

cout << "Using constant +, overloaed, and << overloaded" << endl;
stock[2] = 5 + stock[0]; // g. 5 + fracpri
cout << stock[2] << endl;


cout << "Using + constant, overloaded, and showFraction() function"
<< endl;
stock[2] = stock[0] + 5; // g. fracpri + 5
stock[2].showFraction();


cout << "Using the < operator, overloaded." << endl;
if((stock[0] < stock[1]) == 1) // h. < overloaded
cout << "True" << endl;
else if((stock[0] < stock[1]) == 0)
cout << "False" << endl;


cout << "The += operator overloaded and using the showFraction()
function" << endl;
stock[0] += stock[1]; // k. += overloaded
stock[0].showFraction();

choice = 0; // reset choice to 0 so the menu pops up and
the previous stuff does
// not continue

while(choice != 3 && choice != 4){

cout << "Enter a choice" << endl;
cout << "Press 1 to convert decimal to fraction using a class
constructor" << endl;
cout << "Press 2 to convert fraction to a decimal using float
overloaded, a cast overload" << endl;
cout << "Press 3 to rerun the program" << endl;
cout << "Press 4 to quit the program" << endl;
cin >> choice;

if(choice == 1){
cout << "Enter a decimal" << endl;
cin >> decimal;
fracpri stock5 = decimal; // m. decimal to fraction
// fracpri stock5 = decimal
uses a constructor to convert
// and it is the same as doing
fracpri stock5(decimal)

// the fracpri stock5 is
destroyed when the if(choice ==1)
// scope gets destroyed, so
the constructor always works.
cout << "In fraction form the decimal is" << endl;
cout << stock5 << endl;
cin.ignore(INT_MAX, '\n');
}

else if(choice == 2){
cout << "Enter a fraction" << endl;
cin >> stock[2];
decimal = stock[2]; // m. fraction to decimal
cout << "In decimal form the fraction is" << endl;
cout << decimal << endl;
cin.ignore(INT_MAX, '\n');
}
else if(choice != 3 && choice != 4){
cout << "Invalid entry, please try agian" << endl;
}
}

}while(choice != 4);


return 0;




}
 
R

Rolf Magnus

John said:
// CHO, JOHN

#include<iostream>


class fracpri{
Click to expand...

I've seen better names than "fracpri" :)
int whole;
int numer;
int denom;

public:
// constructors:

fracpri();
fracpri(int w, int n, int d);
fracpri(float f); // float to class constructor

// member functions to show output and get input
void getFraction();
Click to expand...

That function doesn't modify the object, so make it const:

void getFraction() const;
void showFraction();
Click to expand...

void showFraction() const;

Actually, your whole class isn't written with const correctness in mind.
// function and operators to do artimathetic
fracpri addfracts(fracpri &obj1, fracpri &obj2);
Click to expand...

That should rather look like:

fracpri& addfracts(const fracpri &obj1, const fracpri &obj2);
fracpri operator+(fracpri &obj2);
Click to expand...

fracpri operator+(const fracpri &obj2);

same for the others.
fracpri operator-(fracpri &obj2);
fracpri operator*(fracpri &obj2);
fracpri operator/(fracpri &obj2);
Click to expand...

You could make the above operators non-members.
// adding with constants
friend fracpri operator +(int i, fracpri &obj2);
friend fracpri operator +(fracpri &obj1, int i);

// the compare operator, <
bool operator<(fracpri &obj2);
Click to expand...

That should be a non-member too.
// the += operator
fracpri& operator+=(fracpri &obj2);
Click to expand...

fracpri& operator+=(const fracpri &obj2);
// overloading the input and output, >> and << operators.
friend std::istream& operator>> (std::istream& in, fracpri& obj2);
Click to expand...

friend std::istream& operator>> (std::istream& in, const fracpri& obj2);
// std:: is used because
friend std::eek:stream& operator<< (std::eek:stream& out, fracpri const&
obj2);
// namespace std is after it


void reduce();

operator float(); // class to float conversion
Click to expand...

operator float() const; // class to float conversion
};

using namespace std; // namespace needs to be after any use of
friend
// or else msvc++ 6.0 gives errors
Click to expand...

I'd leave the using out completely here.
fracpri::fracpri(){
whole = 0;
numer = 0;
denom = 1; // it is set as 1 so the adding fractions
works with a
// common denominator and not 0
}
Click to expand...

Prefer initialization over assignment:

fracpri::fracpri()
: whole(0),
numer(0),
denom(1)
{
}
fracpri::fracpri(int w, int n, int d){
whole = w;
numer = n;
denom = d;
if(denom == 0)
denom = 1;
reduce();
}
Click to expand...

fracpri::fracpri(int w, int n, int d)
: whole(w),
numer(n),
denom(d ? d : 1)
{
reduce();
}
fracpri::fracpri(float f){ //float type to class type constructor

f += 0.0078125; // .0078125 so numerator is rounded up later
Click to expand...

I'd add a static const class member variable for that magic constant.
And you should generally prefer double over float if you don't have a
very good reason not to.
Oh, and what happens if f is negative? Does your rounding still work as
expected?
whole = int(f);
float flofrac = f - whole; // the fraction part of the number
numer = (flofrac * 64); // .0078125 * 64 = .5 ; so rounded up
numerator
// if orignal fraction
denom = 64;
reduce();
}

void fracpri::getFraction(){
char ch;
cout << "Enter a stock price in the form of " << endl;
cout << "wholenumber-numerator-denominator" << endl;
cin >> whole >> ch >> numer >> ch >> denom;
if(denom == 0)
denom = 1; // fix the denom if it is 0
reduce();
}

void fracpri::showFraction(){

cout << "The stock price is: " << endl;
cout << whole << ' ' << numer << '/' << denom << endl;

}
Click to expand...

Better avoid putting user interaction into such "low level" classes.
Each class should have only one task, and user interaction would be a
second task.
fracpri fracpri::addfracts(fracpri &obj1, fracpri &obj2){
whole = obj1.whole + obj2.whole;
numer = (obj1.numer * obj2.denom) + (obj2.numer * obj1.denom);
denom = obj1.denom * obj2.denom;

reduce();
return *this;
}

fracpri fracpri::eek:perator +(fracpri &obj2){
fracpri temp; // temp is here because *this would modify
// the first object or a in
// c = a + b
temp.whole = whole + obj2.whole;
temp.numer = (numer * obj2.denom) + (obj2.numer * denom);
temp.denom = denom * obj2.denom;

temp.reduce();
return temp;
}
Click to expand...

Don't duplicate code. Just re-use operator+=, which already does the
job:

fracpri fracpri::eek:perator +(const fracpri &obj2)
{
// create a temporary copy, add obj2 to it and return it
return fracpri(*this) += obj2;
}
fracpri fracpri::eek:perator -(fracpri &obj2){
fracpri temp;

// they are converted to improper fractions
// because the second fraction may be larger than the
// first and may cause the final fraction to be negative
// and the whole number to be positive

temp.whole = whole - obj2.whole;
temp.numer = ((whole * denom + numer)*obj2.denom) - ((obj2.whole *
obj2.denom + obj2.numer)*denom);
temp.denom = denom * obj2.denom;

temp.reduce();
return temp;
}

fracpri fracpri::eek:perator *(fracpri &obj2){
fracpri temp;

// convert both to improper
temp.numer = ((whole * denom) + numer) * ((obj2.whole * obj2.denom)
+ obj2.numer);

// the denominator is the two fractions denominators multiplied
together
temp.denom = denom * obj2.denom;

temp.whole = temp.numer/temp.denom;

temp.numer %= temp.denom;

temp.reduce();
return temp;
}
fracpri fracpri::eek:perator /(fracpri &obj2){
fracpri temp;


// convert both to improper
temp.numer = ((whole * denom) + numer) * obj2.denom;

temp.denom = denom * ((obj2.whole * obj2.denom) + obj2.numer);

temp.whole = temp.numer/temp.denom;

temp.numer %= temp.denom;

temp.reduce();

return temp;
}

fracpri operator+(int i, fracpri &obj2){
fracpri temp;

temp.whole = i + obj2.whole;
temp.numer = obj2.numer;
temp.denom = obj2.denom;


return temp;
}

fracpri operator+(fracpri &obj1, int i){
fracpri temp;

temp.whole = obj1.whole + i;
temp.numer = obj1.numer;
temp.denom = obj1.denom;


return temp;
}

bool fracpri::eek:perator<(fracpri &obj2){

// each fractions is multiplied by the other fraction's denominator
so that both fractions
// numerators are the result of a common denominator, which is denom
*obj2.denom
// each fraction's orignal denominator cancels out when the common
denominator is multiplied
// to each of the fractions.

if(((whole * denom + numer)*obj2.denom) < ((obj2.whole * obj2.denom
+ numer)* denom))
return true;
else
return false;
}

fracpri& fracpri::eek:perator +=(fracpri &obj2){
whole += obj2.whole; // same as whole = whole + obj2.whole
numer = (numer * obj2.denom) + (obj2.numer * denom);
denom *= obj2.denom; // same as denom = denom * obj2.denom

reduce();
return *this;
}

istream& operator >>(istream &in, fracpri &obj2){
char ch;
in >> obj2.whole >> ch >> obj2.numer >> ch >> obj2.denom;
Click to expand...

Your first '>> ch' will screw things up. Below, you only write a
whitespace into the stream, and whitepsace is ignored when reading.
if(obj2.denom == 0)
obj2.denom = 1;

obj2.reduce();
return in;
}

ostream& operator <<(ostream &out, fracpri const& obj2){
out << obj2.whole << ' ' << obj2.numer ;
out << '/' << obj2.denom;

return out;
}

fracpri::eek:perator float(){ // class type to float type

// float cast is needed because int divided by int results in int
and not float
// however float divided by int equals a float
float f = float(numer)/denom;

return f + whole;
}

void fracpri::reduce(){
while(numer >= denom){
whole++;
numer -= denom;
}
int count = numer * denom; // a common denominator
for(; count > 1; count--){
if((numer % count == 0) && (denom % count == 0)){ // if count fits
into both
numer /= count; // numerator and denominator without a
remainder,
denom /= count; // then divide both of them by that
// and then continue to count down
}
}
}



int main(){

int choice = 0; // used check if the calculations
should be reran
fracpri stock1; // a. 0 argument constructor
fracpri stock2(5,1,3); // b. 3 argument constructor
float decimal = 0.0;

fracpri stock[3];

do{
cout << "Enter two stock prices that will then be used" << endl;
cout << "with all the functions of this program" << endl;

cout << "Enter a stock price using getFraction" << endl;
stock[0].getFraction(); // c. getfraction function
cout << "Enter a stock price using >> operator" << endl;
cout << "In the form of whole-numerator-denominator" << endl;
cin >> stock[1]; // l. the >> operator

cout << "Using addfracts function and << operator" << endl;
stock[2].addfracts(stock[0], stock[1]); //e. addfracts
cout << stock[2] << endl;;

cout << "Using + operator, overloaded, and showFraction() function"
<< endl;
stock[2] = stock[0] + stock[1]; // f. + , -, *, and / overloaded
stock[2].showFraction();

cout << "Using - operator, overloaded, and << overloaded" << endl;
stock[2] = stock[0] - stock[1]; // f.
cout << stock[2] << endl;

cout << "Using * operator, overloaded, and << overloaded" << endl;
stock[2] = stock[0] * stock[1]; // f.
cout << stock[2] << endl;

cout << "Using / operator, overloaded, and showFraction() function"
<< endl;
stock[2] = stock[0] / stock[1]; // f.
stock[2].showFraction();

cout << "Using constant +, overloaed, and << overloaded" << endl;
stock[2] = 5 + stock[0]; // g. 5 + fracpri
cout << stock[2] << endl;


cout << "Using + constant, overloaded, and showFraction() function"
<< endl;
stock[2] = stock[0] + 5; // g. fracpri + 5
stock[2].showFraction();


cout << "Using the < operator, overloaded." << endl;
if((stock[0] < stock[1]) == 1) // h. < overloaded
cout << "True" << endl;
else if((stock[0] < stock[1]) == 0)
cout << "False" << endl;


cout << "The += operator overloaded and using the showFraction()
function" << endl;
stock[0] += stock[1]; // k. += overloaded
stock[0].showFraction();

choice = 0; // reset choice to 0 so the menu pops up and
the previous stuff does
// not continue

while(choice != 3 && choice != 4){

cout << "Enter a choice" << endl;
cout << "Press 1 to convert decimal to fraction using a class
constructor" << endl;
cout << "Press 2 to convert fraction to a decimal using float
overloaded, a cast overload" << endl;
cout << "Press 3 to rerun the program" << endl;
cout << "Press 4 to quit the program" << endl;
cin >> choice;

if(choice == 1){
cout << "Enter a decimal" << endl;
cin >> decimal;
fracpri stock5 = decimal; // m. decimal to fraction
// fracpri stock5 = decimal
uses a constructor to convert
// and it is the same as doing
fracpri stock5(decimal)

// the fracpri stock5 is
destroyed when the if(choice ==1)
// scope gets destroyed, so
the constructor always works.
cout << "In fraction form the decimal is" << endl;
cout << stock5 << endl;
cin.ignore(INT_MAX, '\n');
}

else if(choice == 2){
cout << "Enter a fraction" << endl;
cin >> stock[2];
decimal = stock[2]; // m. fraction to decimal
cout << "In decimal form the fraction is" << endl;
cout << decimal << endl;
cin.ignore(INT_MAX, '\n');
}
else if(choice != 3 && choice != 4){
cout << "Invalid entry, please try agian" << endl;
}
}

}while(choice != 4);


return 0;




}
Click to expand...

--
Kyle: "Hey, Stan, now that Terrance & Phillip has been taken off the
air, what
are we gonna do for entertainment?"
Stan: "I don't know. We, we could start breathing gas fumes."
Cartman: "My uncle says that smoking crack is kinda cool"
Kyle: "Hey, why don't we watch some of those porno movie thingies?"
 
V

Victor Bazarov

Rolf Magnus said:
I've seen better names than "fracpri" :)


That function doesn't modify the object, so make it const:

void getFraction() const;
Click to expand...

Hmm.. Somehow I suspect that this one actually modifies the object.
void showFraction() const;

Actually, your whole class isn't written with const correctness in mind.


That should rather look like:

fracpri& addfracts(const fracpri &obj1, const fracpri &obj2);
Click to expand...

Shouldn't it actually be static?
fracpri operator+(const fracpri &obj2);
Click to expand...

fracpri operator+(const fracpri &obj2) const;
same for the others.


You could make the above operators non-members.


That should be a non-member too.
Click to expand...

Or at least made 'const'.
fracpri& operator+=(const fracpri &obj2);


friend std::istream& operator>> (std::istream& in, const fracpri& obj2);


operator float() const; // class to float conversion


I'd leave the using out completely here.


Prefer initialization over assignment:
Click to expand...

Prefer referring to FAQ. It contains explanation why initialisation
should be preferred.
fracpri::fracpri()
: whole(0),
numer(0),
denom(1)
{
}

[...other fine advice omitted for brevity...]
Click to expand...

V
 
J

John Cho

Prefer referring to FAQ. It contains explanation why initialisation
should be preferred.
Click to expand...


assignment should be fine as long as i am not trying to initialize const
data members or reference data members

Shouldn't it actually be static?
Click to expand...

what do you mean by static?


i am still trying to figure out why you return by reference if you do nto
use a this pointer
 
K

Keith H Duggar

Wow what a lot of work to try and create a new wheel.

First, boost.org has a fairly nice rational number class that you
should at least take a look at. Second, you don't necessarily need a
whole number portion. However, both of those comments are matters of
context so you may or may not want to listen to them.

However, there is one thing that you definitely should do and that is
implement Euclids GCD algorithm ro reduce instead of this naive one:

void fracpri::reduce(){
while(numer >= denom){
whole++;
numer -= denom;
}
int count = numer * denom; // a common denominator
for(; count > 1; count--){
if((numer % count == 0) && (denom % count == 0)){ // if count fits
into both
numer /= count; // numerator and denominator without a
remainder,
denom /= count; // then divide both of them by that
// and then continue to count down
}
}
}
Click to expand...

The boost rational number class switched over to Euclid's at some
point since the last time I looked so you can find an implementation
there.
 
J

John Harrison

John Cho said:
please tell me why you prefer gobal over methods?
Click to expand...

If you have a global then this will compile

fracpri f;
2.0 * f;
f * 2.0;

Because the fracpri(float) constructor will be implicitly invoked on 2.0.

If you have a method, the first multiplication will not. Basically C++ has
different rules on method parameters and the method object. Since you want
the same rules for all the parameters of *, you should use a global
function.

john
 
J

John Harrison

void fracpri::reduce(){
while(numer >= denom){
whole++;
numer -= denom;
}
int count = numer * denom; // a common denominator
for(; count > 1; count--){
if((numer % count == 0) && (denom % count == 0)){ // if count fits
into both
numer /= count; // numerator and denominator without a
remainder,
denom /= count; // then divide both of them by that
// and then continue to count down
}
}
}
Click to expand...

This is inefficient, since you are risking integer overflow when you say
numer * denom. Instead you should use a greatest common divisor algorithm
(gcd).

void fracpri::reduce(){
while(numer >= denom){
whole++;
numer -= denom;
}
int d = gcd(numer, denom);
numer /= d;
denom /= d;
}

The gcd algorithm can be found in books or on the internet. It's only the
oldest algorithm known to mankind.

john
 
R

Rolf Magnus

John said:
assignment should be fine as long as i am not trying to initialize
const data members or reference data members
Click to expand...

And as long as your members aren't class instances. You're right in that
it typically makes no difference in the generated code for built-in
types. But why make an exception for only non-const, non-reference,
non-class types? Just do it the same way for all. It's called
consistency.
what do you mean by static?
Click to expand...

That you can call the function without an object, but since your
function writes the result to the 'this' objec, it should actually not
be static.
i am still trying to figure out why you return by reference if you do
nto use a this pointer
Click to expand...

Are you talking about the above function being static, or is it a
general question? Returning by reference isn't connected to having a
this pointer. You just have to make sure that the object reffered to
stays alive beyond the function call.
 
R

Rolf Magnus

Victor said:
Hmm.. Somehow I suspect that this one actually modifies the object.
Click to expand...

Oh, right. It reduces...
Shouldn't it actually be static?
Click to expand...

Nope. Look into the implementation. It makes the 'this' object the
result of the addition of obj1 and obj2.
Or at least made 'const'.
Click to expand...

Yes, but only if it stays as a member ;-)
Prefer referring to FAQ. It contains explanation why initialisation
should be preferred.
Click to expand...

Ok, I'll try to do that next time.
 

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