It works, until i enter a second input then it closes

Question

 #include <iostream>


using namespace std;

int main()
{   int a;
    int b;
    int sum;
    string ans = "";
    cout << "Input a directive. Upon it finishing it will terminate. Codes are: \n Calc \n Exit \n";
    cin >> ans;
    if(ans == "Calc")
    {
        cout << "Welcome to Calculator! Put in a number. Press Enter to put in number. \n";
        cin >> a;

        cout << "Next number \n";
        cin >> b;
        sum = a + b;

        cout << sum << " Is the amount! \n";
        cout << "Input a directive. Upon it finishing it will terminate. Codes are: \n Calc \n Exit \n";
        ans = "";    
    }

    if(ans != "Calc")
    {    
        cout << "Okay";    
    }
}

This works, but say if I don't enter Calc, it does nothing, but print out, but if I don't input Calc again, it closes. and if I do put in calc, I can run through it, and when it gives answer, it is fine, then I press any key and it closes out. I am new to this forum/site, not sure if right place.

Answer 1

Well, if you want the program to take again input from the user, then you should write so that it does it:

#include <iostream>
using namespace std;
int main()
{   int a;
    int b;
    int sum;
    while(true) 
    {
         string ans = "";
         cout << "Input a directive. Upon it finishing it will terminate. Codes are: \n Calc \n Exit \n";
         cin >> ans;
         if(ans == "Calc")
         {
             cout << "Welcome to Calculator! Put in a number. Press Enter to put in number. \n";
             cin >> a;

             cout << "Next number \n";
             cin >> b;
              sum = a + b;

              cout << sum << " Is the amount! \n";
          }
          else if(ans == "Exit") 
          {
              cout << "Bye!\n";    
              return 0;
          }
          cout << "Okay\n";    
     }
}