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.