c++ switch run while loop when default

Question

Is there any way to use while loop when user enter wrong number? i.e. while(default) or something. I created goto and it's working but it's lame.

default:
            {
                cin.clear();
                cin.sync();
                cout << "ERROR! Choose other number: ";
                cin >> choose;
                goto again;
            }

I think you are looking for this: https://stackoverflow.com/questions/10828937/how-to-make-cin-take-only-numbers — NathanOliver, Jun 14 '17 at 11:37
No need for goto. A loop around the switch and a continue will suffice. — StoryTeller - Unslander Monica, Jun 14 '17 at 11:40
@StoryTeller Depending on the rest of the loop and `switch` cases, the `continue` might not even be needed. — Some programmer dude, Jun 14 '17 at 11:42
@Someprogrammerdude - Most probably. I just had to comment on the abuse of `goto`. — StoryTeller - Unslander Monica, Jun 14 '17 at 11:43

score -1 · Answer 1 · answered Jun 14 '17 at 12:02

May I suggest:

bool OK;
do
{
    cin >> choose;
    if(OK = !cin.fail())    //if the input is OK
    {
        switch(choose)
        {
        case 1: //do something
            break;
        //case 2: //do something else
        //etc.
        default:
            cin.clear();
            cin.sync();
            cout << "ERROR! Choose other number: ";
            OK = false;
            break;
        }
    }
}
while(!OK);

c++ switch run while loop when default

1 Answers1