Sentinel control fragment

[taraoski]

Hello,

I am new to programming and this forum, so if I am not following protocall here please let me know.

I have the following code fragment that was given to me and the question is:
"What is wrong with the following sentinel control?"

bool done = false;
while (!done)
{
cin >> x;
if (x == sentinelValue)
{
done = true;
}
// code to process x would go here
}

I think the answer is that the if statement does not check for the sentinel value, but I am not sure if that is the correct answer. Any input would be appriciated.

Thanks!

[Azagaros]

You have basically the right idea in your code segment. The loop will continue to run until the sentinel value is reached, for example if the sentinel value is -1, you could enter anything for x until a -1 was reached. I don't know the specifics of your code beyond your short piece but I think you have the right idea.

[taraoski]

@ Azagaros

Basically this is the entire code provided by the teacher and he is asking what is wrong with this fragment, and he has provided nothing else to consider here. I have coded with sentinel and few times, however beside the fact the the if statement does not check for the sentinel I can not understand what else would be wrong with this, if anything.

[Azagaros]

The only thing I could ask, if I am to process the sentinel or not? The code segment you give does process the sentinel, so I cannot make any assumptions with the code without that knowledge but in most cases we don't need to process the sentinel it is designed to stop a process, like in the case a loop.