Question

I'm kind of new to programming, and I am having trouble figuring out why my program isn't running. Below is the code that I wrote for practice. I will comment where it says the error is. So the error that I'm getting is "error: no match for 'operator>>' (operand types are 'std::istream {aka std::basic_istream<char>}' ". I'm not sure why I'm getting this because I added the library <iostream> at the top. Thank you.

Code:
#include <iostream>

using namespace std;

class Math
{
int num1, num2;

public:
void set_values(int, int);

int add()
{
int resultAdd;

resultAdd = num1 + num2;
return resultAdd;
}

int sub()
{
int resultSub;

resultSub = num1 - num2;
return resultSub;
}
};

void Math::set_values(int x, int y)
{
num1 = x;
num2 = y;
}

int main()
{
Math frstNum, secNum, result;
int choice;

cout << "Would you like to add or subtract?" << endl;
cout << "1: Add" << endl;
cout << "2: Subtract" << endl;
cin >> choice;

switch(choice)
{
case 1:
cout << "Enter first number to add: ";
cin >> frstNum; //The error starts at this line. I'm assuming that since the error starts here, it will keep giving me errors on every cin as well.
cout << "Enter second number to add: "; //Also, did I use the classes and objects correctly?
cin >> secNum;
result.set_values(frstNum, secNum);
cout << "Result: " << result.add() << endl;
break;
case 2:
cout << "Enter first number to subtract: ";
cin >> frstNum;
cout << "Enter second number to subtract: ";
cin >> secNum;
result.set_values(frstNum, secNum);
cout << "Result: " << result.subtract() << endl;
break;
default:
cout << "Sorry, you're stupid. =)" << endl;
break;
}

return 0;
}

Answer 1

Check the code below:

#include "stdafx.h"
#include <iostream>

using namespace std;

class Math
{
   int num1, num2;

public:
   void set_values(int, int);

   int add()
   {
       int resultAdd;

       resultAdd = num1 + num2;
       return resultAdd;
   }

   int sub()
   {
       int resultSub;

       resultSub = num1 - num2;
       return resultSub;
   }
  
};

void Math::set_values(int x, int y)
{
   num1 = x;
   num2 = y;
}

int main()
{
   Math result;
   int frstNum, secNum;
   int choice;

   cout << "Would you like to add or subtract?" << endl;
   cout << "1: Add" << endl;
   cout << "2: Subtract" << endl;
   cin >> choice;

   switch (choice)
   {
   case 1:
       cout << "Enter first number to add: ";
       cin >> frstNum; //The error starts at this line. I'm assuming that since the error starts here, it will keep giving me errors on every cin as well.
       cout << "Enter second number to add: "; //Also, did I use the classes and objects correctly?
       cin >> secNum;
       result.set_values(frstNum, secNum);
       cout << "Result: " << result.add() << endl;
       break;
   case 2:
       cout << "Enter first number to subtract: ";
       cin >> frstNum;
       cout << "Enter second number to subtract: ";
       cin >> secNum;
       result.set_values(frstNum, secNum);
       cout << "Result: " << result.sub() << endl;
       break;
   default:
       cout << "Sorry, you're stupid. =)" << endl;
       break;
   }

   return 0;
}

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