C++ Switch Statement - Giving player another chance to choice

Question

This is a block of code from a book I've been studying and trying to improve upon, but I'm having trouble finding a way to give the player another chance at selecting the difficulty after entering the default choice. This is a very simple console text-based game and when the player chooses an incorrect choice, the game doesn't allow the player to re-choose.

 int _tmain(int argc, _TCHAR* argv[])
 {
     cout << "Difficulty Levels\n\n";
     cout << "1 - Easy\n";
     cout << "2 - Normal\n";
     cout << "3 - Hard\n\n";

     int choice;
     cout << "Choice: ";
     cin >> choice;


     switch (choice)
     {
      case 1:
         cout << "You picked Easy\n";
         break;
     case 2:
         cout << "You picked Normal\n";
         break;
     case 3:
         cout << "You picked Hard\n";
         break;
     default:
         cout << "Your choice is invalid.\n";
     }

     system("pause");
     return 0;
 }

Answer 1

You can refactor the switch into a function, which can be called whenever the player wants to change their difficulty choice.

int choose()
{
    int choice;
    cout << "Difficulty Levels\n\n";
    cout << "1 - Easy\n";
    cout << "2 - Normal\n";
    cout << "3 - Hard\n\n";

    cout << "Choice: ";
    cin >> choice;

    switch (choice)
    {
     case 1:
        cout << "You picked Easy\n";
        break;
    case 2:
        cout << "You picked Normal\n";
        break;
    case 3:
        cout << "You picked Hard\n";
        break;
    default:
        cout << "Your choice is invalid.\n";
        choice = 0; //this will signal error
    }
    return choice;
}

int _tmain(int argc, _TCHAR* argv[])
{
    int choice = 0;
    while(choice == 0){choice = choose();};  
    system("pause");
    return 0;
}

Now whenever the player decides to change difficulty (maybe they enter a special letter) you can use choice = choose() to alter the difficulty.