问题
struct place
{
char name[80+1];
double latitude;
double longitude;
};
struct node
{
struct place city;
struct node *next;
};
struct node *head;
head
head -> city
head -> next
head -> city -> name
head -> next ->city.name
These kinds of tasks always make me lose points on exams, anyone kind enough to explain? It's asking about what types the variables mentioned are, and I guess stuff like head are simply a pointer towards the value of entire structure node?
回答1:
In the later snippet at the later part,
head -> city -> name
is wrong, because, city is not a pointer type. You need to use the dot operator (.) to access a member of a non-pointer structure variable. Just the way you've used it in
head -> next ->city.name
Other than that, syntactically, the snippets appear fine.
Just to add, as a basic sanity, you should be checking for non-NULL-ity of a pointer before de-referencing to avoid invoking undefined behavior.
来源：https://stackoverflow.com/questions/37658508/under-these-declarations-what-types-are-the-following-expressions-and-are-they