Thread: ADT - destroyQueue; count vs null pointer

When writing the destroyQueue function for my queue ADT, is there really that much of a difference in using

Code:

while(queue->count)

as opposed to

Code:

while(queue->front != NULL)

for the control statement of the loop that steps through the queue and destroys it? Using the assumption that the rest of the code and functions are bug free, and that the queue counts and next pointers are working correctly to facilitate those conditions. I don't see a difference, but then, I'm just a student and may not be seeing some sort of subtle potential pitfall.

Originally Posted by Salem

In fact, you wouldn't use count directly either, but say
while ( !queue.empty() )

Hey, I hadn't thought of that. I guess that adds a third option to try.

Originally Posted by Salem

Well, if you use count, then you help to minimise the scope of knowing that the queue is built on a linked list to only the insert and delete functions.

But how is someone going to know one way or the other if they never see the actual code? If they're seeing the code, they're going to find out anyway. Also, even if the control statement uses either queue->count or !queueEmpty(queue), if they're looking at that then they're also looking at the rest of the code too, so they'll see from the inside of the loop that it's a linked list (as the nodes get deleted and queue->front gets refreshed).

Thanks for the input and ideas Salem.