A simple console based calculator with data validation.

math_input.cpp

#include <iostream>
#include <limits>
int main()
{
    int number1 , number2;
    char sign;
    
    while (true) {
        std::cout << "Enter 2 numbers seperated by a  + or - sign \n";
       
        if (!std::cin.fail() && (sign == '-' || sign == '+')) {
            break;
        }
        else {
            std::cin.clear(); // Clears the fail bit.
            std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
        }


    }
  
    if (sign == '-') {
        number2 *= -1;
    }
    std::cout << "Your answer is " << number1 + number2;
}