What is the difference between this two declarations

Question

struct p{
int x,y;
};
and
struct {
int x,y;
} p;

Answer 1

The first declare a struct with name p. The second declare a variable p than refer to an unamed struct

Answer 2

so I can not declare an instance of p in second example

How can I use the second way ?

Answer 3

I got it thanks master KrOW
Soo it is just an instance of unnamed struct

Answer 4

What is the benefit of unnamed struct or how I can write a fucntion that returns an instance of unnamed struct

Answer 5

What is exactly happening when I write "typedef" befor unnamed struct

Why The address of unnamed struct was just in digits

Thanks for help

Answer 6

No because p is not a struct but it will be yet an instance of an unamed struct (eg you can access to members like p.x or p.y)

Answer 7

See here https://stackoverflow.com/questions/612328/difference-between-struct-and-typedef-struct-in-c