Difference between -> and . in a struct?

Question

If I have a struct like

struct account {    int account_number; }; 

Then what's the difference between doing

myAccount.account_number; 

and

myAccount->account_number; 

or isn't there a difference?

If there's no difference, why wouldn't you just use the . notation rather than ->? -> seems so messy.

Answer 1

-> is a shorthand for (*x).field, where x is a pointer to a variable of type struct account, and field is a field in the struct, such as account_number.

If you have a pointer to a struct, then saying

accountp->account_number; 

is much more concise than

(*accountp).account_number; 

Answer 2

You use . when you're dealing with variables. You use -> when you are dealing with pointers.

For example:

struct account {    int account_number; }; 

Declare a new variable of type struct account:

struct account s; ... // initializing the variable s.account_number = 1; 

Declare a as a pointer to struct account:

struct account *a; ... // initializing the variable a = &some_account;  // point the pointer to some_account a->account_number = 1; // modifying the value of account_number 

Using a->account_number = 1; is an alternate syntax for (*a).account_number = 1;

I hope this helps.