A calculator program problem?

Greetings;
I am trying to total up this operation but for some reason my calcu;ator isn't calculating. Does anyone know why? Does anyone know MVC++ really well. My question is how do you use the debugger to debug the program and watch the program you created step-by-step?

Here is my code

Code:

#include <iostream>		
#include<string>
#include <cassert>
using namespace std;

string apply(char operation);
int factorial(int n);

int op1, op2, total;
char operation;

int main()
{

	cout << "Please enter: \n"
		 << "+ to add two numbers;\n"
		 << "- to subtract two numbers:\n"
		 <<	"* multiply two numbers;\n"
		 <<	"/ divide two numbers.\n";
	
	cin >> op1 >> operation >> op2;
	total = operation;
	cout <<  op1 << operation << op2 << "=" << total <<endl;
	return 0;

}

string apply(char operation)
{
	switch (operation)
	{
	
	case '+': "op1 + op2";
		break;
	case '-': "op1 - op2";
		break;
	case '*': "op1 * op2";
		break;
	case '/': "op1 / op2";
		break;
	default:
		cerr << "You selected an invalid operation!" << endl;
		return " ";
		
	}
}


\A work in progress... pay no attention
\int factorial(int n)
\{
\	assert( n >= 0);
\	double product = 1;
\	while ( n > 1 )
\	{
\		product *= n;
\		n--;
\	}
\return product;
\}

Ctrl+F10 = run to cursor
F11 = step into
F10 = step over
Shift+F11 = step out

Use the watch feature to see the values of your variables during runtime.

You've set total to equal your char operation btw. This isn't right.

The problem starts after the line

Code:

cin >> op1 >> operation >> op2;

in main. The next line should invoke apply like this

Code:

total = apply(operation );

And also should the apply-function look a little different. Change each case statement to return the result like

Code:

        case '+': return (op1 + op2);
		//break; 
	case '-': return (op1 - op2);
		//break; 
	case '*': return (op1 * op2);
		//break;
	case '/': return op1 / op2;
		//break;
	default:
		cerr << "You selected an invalid operation!" << endl;
		return 0;//Cases little trouble because an arithmetric operation can return 0

All break(s) are unnessesary in this case because the function exits after a return statement. And the last problem is..... I´ll leave it to you to find it

Code:

total = apply(operation );

This is giving this error:
C:\Program Files\Microsoft Visual Studio\MyProjects\ch9sec51\calculate.cpp(34) : error C2679: binary '=' : no operator defined which takes a right-hand operand of type 'class std::basic_string<char,struct std::char_traits<char>,class std::allocator<
char> >' (or there is no acceptable conversion)

How do I fix this?

And the last problem is..... I´ll leave it to you to find it

Hmm I hope you have tried.. anyway change

Code:

//string apply(char operation);
int apply(char operation);

Don´t forget to do the same thing on the function definition.