C++ Program Fraction

[d0ugg]

Hi, Iam writing a code for my class and I cant figure out how to solve it. I will be glad if somebody can teach me how to do something to correct it.
The program is divided it 3 parts.

     switch (symbol) 
     { 
      case '+': 
        read_frac(fraction* f);
        print_frac(fraction& a_fraction);
        answer = add(fraction f1, fraction f2); 
        nome = "sum"; 
        break; 
     case '-': 
        read_frac(fraction* f);
        print_frac(fraction& a_fraction);
        answer = sub(fraction f1, fraction f2);
        nome= "difference"; 
        break; 
     case '*': 
        read_frac(fraction* f);
        print_frac(fraction& a_fraction);
        answer = mult(fraction f1, fraction f2);
        break; 
     case 'x': 
        answer = mult(fraction f1, fraction f2);
        nome = "product";
        break;
     case '/': read_frac(fraction* f);
               print_frac(fraction& a_fraction);
        answer = div(fraction f1, fraction f2);
        nome = "quotient";
        break; 
      } 
      cout << "The " << nome << " of " <<  << " and " << fraction << " is "<< answer << "\n"; 

The bold part if where Iam having trouble. I don't know exactly what I have to do to compile


Thanks ,
doug

[sicarie]

Hi, Iam writing a code for my class and I cant figure out how to solve it. I will be glad if somebody can teach me how to do something to correct it.
The program is divided it 3 parts.

     switch (symbol) 
     { 
      case '+': 
        read_frac(fraction* f);
        print_frac(fraction& a_fraction);
        answer = add(fraction f1, fraction f2); 
        nome = "sum"; 
        break; 
     case '-': 
        read_frac(fraction* f);
        print_frac(fraction& a_fraction);
        answer = sub(fraction f1, fraction f2);
        nome= "difference"; 
        break; 
     case '*': 
        read_frac(fraction* f);
        print_frac(fraction& a_fraction);
        answer = mult(fraction f1, fraction f2);
        break; 
     case 'x': 
        answer = mult(fraction f1, fraction f2);
        nome = "product";
        break;
     case '/': read_frac(fraction* f);
               print_frac(fraction& a_fraction);
        answer = div(fraction f1, fraction f2);
        nome = "quotient";
        break; 
      } 
      cout << "The " << nome << " of " <<  << " and " << fraction << " is "<< answer << "\n"; 

The bold part if where Iam having trouble. I don't know exactly what I have to do to compile


Thanks ,
doug

Doug-

What part are you having trouble with? Have you tried compiling it? What error message do you get?

[DeMan]

You seem to be passing a type as well as it's instance to most methods
eg
instead of

answer = div(fraction f1, fraction f2);
 

consider

answer = div(f1, f2);
 

This applies to almost every method you call.

Also, your final print

      cout << "The " << nome << " of " <<  << " and " << fraction << " is "<< answer << "\n";
 

may not do quite what you want, consider

      cout << "The " << nome << " of " <<  f1 << " and " << f2 << " is "<< answer << "\n"; 
 

[d0ugg]

Okay, thanks for the message. I will try to do that and see if I can compile. Thanks once again,
Doug

[d0ugg]

I did some corrections and still got an error.

Here is the error that the compile shows:

c:\documentos\p rogramas\calcul ator\fraction\f raction\calc.cp p(65) : error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'fraction' (or there is no acceptable conversion).

Here is the code again:

#include <iostream>
#include <string>
#include "fraction.h"
using namespace std;
 
fraction mult(fraction f1, fraction f2)
{
    fraction f10;
    int common;
 
    f10.numerator = (f1.numerator * f2.numerator);
    f10.denominator = (f1.denominator * f2.denominator);
 
    common = gcd(f10.numerator, f10.denominator);
    f10.numerator /= common;
    f10.denominator /= common;
 
    return f10;
}
 
fraction add(fraction f1, fraction f2)
{
    fraction f10;
    int common;
 
    f10.numerator = (f1.numerator + f2.numerator);
    f10.denominator = (f1.denominator + f2.denominator);
 
    common = gcd(f10.numerator, f10.denominator);
    f10.numerator /= common;
    f10.denominator /= common;
 
    return f10;
}
 
fraction sub(fraction f1, fraction f2)
{
    fraction f10;
    int common;
 
    f10.numerator = (f1.numerator - f2.numerator);
    f10.denominator = (f1.denominator - f2.denominator);
 
    common = gcd(f10.numerator, f10.denominator);
    f10.numerator /= common;
    f10.denominator /= common;
 
    return f10;
}
 
fraction div(fraction f1, fraction f2)
{
    fraction f10;
    int common;
 
    f10.numerator = (f1.numerator / f2.numerator);
    f10.denominator = (f1.denominator / f2.denominator);
 
    common = gcd(f10.numerator, f10.denominator);
    f10.numerator /= common;
    f10.denominator /= common;
 
    return f10;
}
 
 
void read(fraction f)
{
    int numerator;
    int denominator;
 
    cout << "Enter your numerator: ";
        cin >> numerator;
    cout << "Enter your denominator: ";
    cin >> denominator;
 
}    
 
void print(fraction a_fraction)
{
 
    cout << a_fraction.numerator << "/" << a_fraction.denominator << endl;
}
 
 
int gcd (int u, int v)
{
    u = (u < 0) ? -u : u;
    v = (v < 0) ? -v : v;
 
while (u > 0)
{
    if (u < v)
{
    int t = u;
    u = v;
    v = t;
}
    u -= v;
}
return v;
}
----------------------------------
 
 
 
#include <iostream>
#include <string>
#include "fraction.h" 
using namespace std;
 
int main() 
{ 
    fraction f1;
    fraction f2;
    fraction f10;
    fraction f;
    fraction a_fraction;
 
    int answer;
    char symbol = ' ';
    string nome;
 
   while (true)
   { 
    cout << "+\tADD\n";
    cout << "-\tSUBTRACT\n";
    cout << "* or x\tMULTIPLY\n";
    cout << "/\tDIVIDE\n";
    cout << "E\tEXIT\n";
    cout << "What operation do you want to use?: ";
        cin >> symbol;
        if (symbol == 'e' || symbol == 'E')
            exit(0);
 
     switch (symbol) 
     { 
      case '+': 
          read(f);
          print(a_fraction);
          add(f1, f2);
        nome = "sum"; 
        break; 
     case '-': 
        read(f);
        print(a_fraction);
        sub(f1, f2);
        nome= "difference"; 
        break; 
     case '*': 
        read(f);
        print(a_fraction);
        mult(f1, f2);
        break; 
     case 'x': 
        read(f);
        print(a_fraction);
        mult(f1, f2);
        nome = "product";
        break;
     case '/': 
        read(f);
        print(a_fraction);
        div(f1, f2);
        nome = "quotient";
        break; 
      } 
      cout << "The " << nome << " of " << f1 << " and " << f2 << " is " << answer << "\n"; 
   }
   return 0;
}
-----------------------
 
struct fraction
{
    int numerator;
    int denominator;
};
 
fraction mult(fraction f1, fraction f2);
fraction add(fraction f1, fraction f2);
fraction sub(fraction f1, fraction f2);
fraction div(fraction f1, fraction f2);
void read(fraction f);
void print(fraction a_fraction);
int gcd (int u, int v);

Thank you ,

Doug

[sicarie]

Doug-

I'm not sure if those programs were all together or in different files, what is on line 65? Can you post 64,65, and 66?

[Ganon11]

Is fraction a class you have made? If so, you will have to write your own << code for it - use the function header:

friend ostream& fraction::operator<<(ostream& out, fraction& value);
// Order of arguments may be switched

[d0ugg]

The line of the code that have problem is:


cout << "The " << nome << " of " << f1 << " and " << f2 << " is " << answer << "\n";
}

--

Error message:

c:\documentos\p rogramas\calcul ator\fraction\f raction\calc.cp p(65) : error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'fraction' (or there is no acceptable conversion)

Thanks once again.