How do the "->" and "." member access operations differ in C

Question

I have looked at some resources to tell me how -> and . are different, but they seem to do the same thing. Does -> act like a dot operator on a struct?

Answer 1

. is used when you have a struct, and -> is used when you have a pointer to a struct. The arrow is a short form for dereferencing the pointer and then using .: p->field is the same as (*p).field.

Answer 2

They are almost the same thing. The only difference is that "->" takes a pointer to a struct on the left side while "." takes a struct; "->" deferences (i.e. follows) the pointer before accessing the struct member. So,

struct foo bar;
bar.x = 0;

is the same as:

struct foo bar;
struct foo *diddly = &bar;
diddly->x = 0;