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[Sspangler]

I'm getting the error on add, subtract, multiply and divide. I'm sure i'm missing something really simple but for the live of me i can't figure out what it is.

The main cpp file:

#include <iostream>

#include "lab 2.h"

using namespace std;

int main ()
{
	int choice;
	calculator num1, num2;

	cout << "What would you like to do? add, subtract, multiply or divide? (1-4)" << endl;
	cin >> choice;

	if (choice == 1)
		add(num1, num2);
	if (choice == 2)
		subtract(num1, num2);
	if (choice == 3)
		multiply(num1, num2);
	if (choice == 4)
		divide(num1, num2);


	system ("pause");
	return 0;
}

The header:

#include <iostream>

using namespace std;

class calculator 
{
public:
	void add(int num1, int num2);
        void subtract(int num1, int num2);
	void multiply(int num1, int num2);
	void divide(int num1, int num2);

};

#include <iostream>

#include "lab 2.h" 

using namespace std;



void calculator::add(int num1, int num2)
{
	cout << "Enter 2 numbers" << endl;
	cin >> num1;
	cin >> num2;

	cout << num1 + num2;
}

void calculator::subtract(int num1, int num2)
{
	cout << "Enter 2 numbers" << endl;
	cin >> num1;
	cin >> num2;

	cout << num1 - num2;
}

void calculator::multiply(int num1, int num2)
{
	cout << "Enter 2 numbers" << endl;
	cin >> num1;
	cin >> num2;

	cout << num1 * num2;
}

void calculator::divide(int num1, int num2)
{
	cout << "Enter 2 numbers" << endl;
	cin >> num1;
	cin >> num2;

	cout << num1 / num2;
}

I don't have a lot of experience with programming so sorry if this is a stupid question.

[zb0S216C]

Your calculator functions reside within a class. In order to access non-static functions of a class, you need to create an object, or instance, of that class. For instance:

calculator Calculator_; // "Calculator_" is an object/instance.

// Now we can use the functions:
Calculator_.add( ..., .... );

Though, you don't actually need a class to declare your functions. Instead, what you could do (preferable) is declare your functions in the global name-space. For example:

#include <iostream>

// Global name-space starts here...
int Add( int A_, int B_ );

// Global name-space ends here...

int main( )
{
  int ValueA_( 10 );
  int ValueB_( 20 );

  std::cout << Add( ValueA_, ValueB_ );

  return( 0 );
}

// Global name-space starts here again...
int Add( int A_, int B_ )
{
  return( A_ + B_ );
}

// Global name-space ends ends here for this file. 

See more information here on functions: http://www.cplusplus.com/doc/tutorial/functions/ and here for classes: http://www.cplusplus.com/doc/tutorial/classes/ . In fact, see here for just about anything: http://www.cplusplus.com/doc/tutorial/

_Wazzak

[Sspangler]

I know that their are easier ways then using a class but i need practice with how to wright one so i decided to start of with just a simple problem. But anyway i did what you suggested with making

calculator Calculator_;

but now im getting error C2664: cannot convert parameter 1 from "calculator" to "int"

so my code now looks like this:

if (choice == 1)
		Calculator_.add(num1, num2);
	if (choice == 2)
		Calculator_.subtract(num1, num2);
	if (choice == 3)
		Calculator_.multiply(num1, num2);
	if (choice == 4)
		Calculator_.divide(num1, num2);

[zb0S216C]

"num1" and "num2" are of type "calculator" can cannot be converted to an "int"; hence the error. "num1" and "num2" need to be of type "int" for your functions to work.

int main( )
{
  calculator Calculator_;

  int Choice_( -1 );
  std::cin >> Choice_;

  int ValueA_( 0 );
  std::cin >> ValueA_;

  int ValueB_( 0 );
  std::cin >> ValueB_;

  if( Choice_ == 1 )
    Calculator_.add( ValueA_, ValueB_ );

  else if( Choice_ == 2 )
    Calculator_.subtract( ValueA_, ValueB_ );

  // ...and so on.
}

_Wazzak

[Sspangler]

I got it. Thanks for the help, much appreciated.