How to Limit Input to Numbers Only

Question

I recently created a program that will create a math problem based on the user input. By entering either 1-4 the program can generate a problem or the user can quit by ente

Answer 1

1. Read a single character
2. If this character is a digit, use it.
3. If this character wasn't a digit, goto 1.

Actually, forget about step 2. Just check whether it was one of the digit characters you actually want ('1', '2', '3', '4', '5'):

char choice;

while(cin.get(choice)){
  if(choice == '5')
    break;

  switch(choice){
    default: printWrongCharacterMessage(); break;
    case '1': do1Stuff(); break;
    case '2': do2Stuff(); break;
    case '3': do3Stuff(); break;
    case '4': do4Stuff(); break;    
  }
}