The following code is inside a do while loop choice is suppo

The following code is inside a do while loop. choice is supposed to be an integer input by the user. However, when a character is put instead of an integer, the code loops infinitely. Putting break; or exit(); after the catch statements terminates the whole program, which is wrong. How can i fix this?

#include <iostream>

#include <vector>

#include <iomanip>

#include<stdlib.h>

#include <cctype>

#include \"MyGrades.h\"

using namespace std;

int main ()

{

   int choice; // user input for menu selection

   double quiz, program, test; // user input for grades

   MyGrades a; // class declaration

   cout << fixed << setprecision(2);

   cout << \"Welcome to My Grades APP. \" << endl;  

   do {

       cout << \"\ Main Menu\" << endl << endl;

       cout << \" 1. Set A quiz Grade\" << endl

          << \" 2. Set A Programming Assignment Grade\" << endl

   << \" 3. Set A Test Grade\" << endl

          << \" 4. Show All quiz Grades\" << endl

          << \" 5. Show All Programming Assignment Grades\" << endl

          << \" 6. Show All Test Grades\" << endl

          << \" 7. Show Overall Grades\" << endl

          << \" 9. Exit The Program\" << endl << endl;

      

       cout << \"Enter your choice ---> \";

       cin >> choice;

       try {

           if (!isdigit(choice))

               throw choice;

       } catch (char choice) {

       cout << \"Error *** Incorrect input - You entered a character\" << endl;

           cout << \"Enter a Positive Integer\" << endl << endl;

       }

  

           switch(choice)

           {

               case 1: cout << \"\ Enter Quiz grade: \";

       cin >> quiz;

       a.setQuiz(quiz);

                   break;

               case 2: cout << \"\ Enter A Programming Assignment grade: \";

       cin >> program;

       a.setProgram(program);

                   break;

               case 3: cout << \"\ Enter A Test grade: \";

       cin >> test;

       a.setTest(test);

                   break;

               case 4: cout << \"\ Show All Quiz grades with Average.\" << endl;

       a.getQuiz();

                   break;

               case 5: cout << \"\ Show All Programming Assignment grades with Average\" << endl;

       a.getProgram();

                   break;

               case 6: cout << \"\ Show all Test Grades with Average\" << endl;

       a.getTest();

           break;

               case 7: cout << \"\ Show Overall Grades.\" << endl;

       a.showAll();

                   break;

               case 9:

                   break;

               default:

       cout << \"\ Invalid Choice\" << endl;

                   break;

           }

      

   } while (choice != 9);

   cout << \"\ Implemented by Emily Leyendecker and Maxwell Yi\" << endl

   << \"February - 2017\" << endl << endl;

   return 0;

}

Solution

Answer:

goto for keep the program alive even in case of a non int input and the 2nd one is the solution of infinite loop .Here is the fixed code :

#include<iostream>

#include<cstdlib>
#include<fstream>
#include<cmath>

using namespace std;
int main()
{
   int a[30];
   int s;
   fstream file;
   int sum=0;
   int q=0;
   double averge;
   double st;
   int standard_deviation;
   int avg;
   int square;
   cout<<\"\\t How many person\'s tempurature you wanna save \";
   cin>>s;
   int temp=0;
   for(int i=0;i<s;i++)
   {
   a[i]=rand()%100;
     
   }
   cout<<\"\\t \\t YOUR DATA HAS been saved in a file check file for results...\"<<endl;
   file.open(\"temps.txt\",ios::out|ios::app|ios::in);
  
       for(int i=0;i<s;i++)
       {
           file<<a[i]<<endl;
           sum=sum+a[i];
           avg=sum/s;
          
          
           st=avg-a[i];
           int s=-1*(st);
           square=s*s;
           temp=temp+square;
           temp=temp/s;
           standard_deviation=sqrt(temp);
          
          
       }
       file<<\"Mean =\"<<avg<<endl;
   file<<\"standard deviation =\"<<standard_deviation<<endl;
   file.close();
  
}