Getting a infinite loop when error checking

[avandi]

Why does this create a infinite loop if I enter a char?



//////////////////////////////////////////////////////////////////////
//CREATE ITEM
//////////////////////////////////////////////////////////////////////
void World::CreateItem()
{
int answer = 0;
do
{
cout << endl << "Item Level: ";
cin >> answer;

}while(!GoodChoice(0, answer, 50));
FirstItem->GenerateItem(this, answer);
}

//////////////////////////////////////////////////////////////////////
//GOOD CHOICE
//////////////////////////////////////////////////////////////////////
int World::GoodChoice(int lowest, int Num, int highest)
{

if ((Num <= lowest) || (Num > highest))
{
//A bad choice so print a message and return false
cout << endl << "I don't understand that choice." << endl;
return 0;
}

//Since we haven't returned, the choice is good
return 1;
}

[wbartley]

What does your output look like?

[avandi]

I don't understand that choice.

Item Level:

I don't understand that choice.

Item Level:

I don't understand that choice.

Item Level:

Over and over and over, I need to ctrl c out of it to stop it

[avandi]

it works if I enter a number but it's when I enter a char like an 'a'

[Graham]

But you are asking for an integer. 'a' is not an integer, so answer gets the value 0, which is a bad choice according to your code. If you want a character, why aren't you asking for a character?

[avandi]

thats why I have the error checking in place, if someone types something other than what I want I want it to display the message "I don't understand that choice." then go back to
Item Level: and wait for another entry.

[Philip Nicoletti]

When you enter an "a", the read fails, which sets the
failbit for the stream (cin in your case) AND does not
move the position in the stream (still points to the "a").

If an error occurs, you need to clear the state of the stream
and throw out the rest of the stream buffer :

cin >> answer;

if (cin.fail())
{
     cin.clear();
     cin.ignore(100,'\n');
}

[avandi]

Thanks a lot that did it..