Adding a fractions and classes - Woot - c++

Question

Hey guys to start off I will say that I have looked into a lot of similar programs before posting this question and still need some help. My problem lies in the addition fraction class function where I need to add one fraction to another. I have one class and am currently working with to instances of that class (fractionObject and fractionObject2). I am storing my fractions separately, one in fractionObject and one in fractionObject2. How can I add these in my fraction class function 'Add'?
Any tips will be much appreciated! Thanks for your time!
#include <iostream>
#include <string>
#include <sstream>
using namespace std;
// Regular prototypes
int stringToNumber(const string &Text);
int GCD(int, int);
int LCM(int, int);
class fraction{
public: // Access Specifier
int numerator;
int denominator; // Can never be 0
// Function Prototypes
fraction();
void setNumDen();
void reduce();
void add();
};
// Member functions definitions
fraction::fraction()
{
numerator = 0;
denominator = 0;
}
void fraction::setNumDen()
{
string numString;
string denString;
do{
cout << "Enter a numerator and denominator of fraction 1 separated by whitespace: ";
getline(cin, numString, ' ');
getline(cin, denString);
if (denString == "0")
cout << endl << "Please enter a number that isn't zero." << endl;
} while (denString == "0"); // Making sure denominator is not zero
numerator = stringToNumber(numString);
denominator = stringToNumber(denString);
}
void fraction::reduce()
{
int leastCommonMultiple = 0;
leastCommonMultiple = LCM(numerator, denominator);
numerator /= leastCommonMultiple;
denominator /= leastCommonMultiple;
}
void fraction::add()
{
int leastComDen;
}
int main()
{
fraction fractionObject, fractionObject2;
fractionObject.setNumDen();
fractionObject2.setNumDen();
// Reducing and displaying the reduced fractions
fractionObject.reduce();
fractionObject2.reduce();
cout << "Reduced Fraction 1 = " << fractionObject.numerator << "/" << fractionObject.denominator << "\t" << "Reduced Fraction 2 = " << fractionObject2.numerator << "/" << fractionObject2.denominator << endl;
// Adding and displaying the fractions
system("pause");
return 0;
}
// Function to convert string to number
int stringToNumber(const string &Text)//Text not by const reference so that the function can be used with a
{ //character array as argument
stringstream ss(Text);
int result;
return ss >> result ? result : 0;
}
// result=GCD(a,b)
int LCM(int a, int b) {
int temp = 0;
while (b != 0) {
temp = b;
b = a%b;
a = temp;
}
return a;
}
// result=LCM(a,b);
int GCD(int a, int b) {
int result = 0;
result = a * (b / LCM(a, b));
return result;
}

Answer 1

No complete answer here, but add should have two const fraction& arguments and return a temporary fraction object. You might rename it operator+. Many libraries add a += operator that doesn't require making a temporary object. C++11 allows you to reduce the overhead of these temporary objects with a move constructor.
As for the implementation, here’s a hint: 1/6 + 1/9 = (9+6)/54 = 5/18. I notice you already have a reduce function.