There might be a situation where you end up having a value of sym that is beyond the number of items in the list. For example, it could be sym=3 or sym=0. If this happens, then the switch function will return NULL.
There might be a situation where you end up having a value of sym that is beyond the number of items in the list. For example, it could be sym=3 or sym=0. If this happens, then the switch function will return NULL.