/*
   testfunc14.cpp
   CIS 150
   6/9/2005
   David Klick
   
   This program demonstrates a useful data validation
   function for use with menus.
*/

#include <iostream>
#include <cctype>
using std::cin;
using std::cout;

char getChoice(char* prompt, char* allowed);
void displayChoice(char* msg);

int main(void) {
   char choice;
   do {
      // display menu
      cout << "Menu\n\n"
         "    (F)irst\n\n"
         "    (S)econd\n\n"
         "    (E)nd\n\n";

      // get user choice
	  choice = getChoice("Enter choice: ", "FfSsEe");
	  choice = toupper(choice);  // convert to upper case
	  
     // process choice
     switch (choice) {
     case 'F':
        displayChoice("the first choice");
        break;
     case 'S':
        displayChoice("the second option");
        break;
     }	              	            
   } while (choice != 'E');

   cout << "Normal program terminiation\n\n";
   return 0;
}

char getChoice(char *prompt, char *allowed) {
   char ch;
   char *ptr;
   do {
      cout << prompt;
      cin >> ch;
      ptr = strchr(allowed, (int)ch);
      if (ptr == NULL) {
         cout << "Error: Invalid choice\n";
      }
   } while (ptr == NULL);
   return ch;
}

void displayChoice(char* msg) {
   cout << "You chose " << msg << '\n';
}