C Programming - Structures, Unions, Enums - Discussion

(*d).month is valid I think.

@All.

Here, It's told that assigning the value using 'pdt' variable.

So, option D is correct.

Both d.month and pdt->month will work fine.

Since d is a object of type struct date, we use '.' in d.month to access or modify value of month of object d.
whereas since pdt is pointer pointing to 'object d' we use pdt->month to access/modify the same.
Code below will print the same output regardless what operator you use.

Code:-
#include<stdio.h>
struct date
{
int day;
int month;
int year;
};

int main()
{
struct date d;
struct date *pdt;
pdt = &d;

pdt->month = 9;
printf("d.month = %d\n", d.month);
printf("pdt->month = %d\n", pdt->month);

d.month = 1;
printf("d.month = %d\n", d.month);
printf("pdt->month = %d\n", pdt->month);
return 0;

OUTPUT:-
d.month = 9
pdt->month = 9
d.month = 1
pdt->month = 1

Both d.month and pdt->month will work fine.

Since d is a object of type struct date, we use '.' in d.month to access or modify value of month of object d.
whereas since pdt is pointer pointing to 'object d' we use pdt->month to access/modify the same.
Code below will print the same output regardless what operator you use.

Code:-
#include<stdio.h>
struct date
{
int day;
int month;
int year;
};

int main()
{
struct date d;
struct date *pdt;
pdt = &d;

pdt->month = 9;
printf("d.month = %d\n", d.month);
printf("pdt->month = %d\n", pdt->month);

d.month = 1;
printf("d.month = %d\n", d.month);
printf("pdt->month = %d\n", pdt->month);
return 0;
}

OUTPUT:-
d.month = 9
pdt->month = 9
d.month = 1
pdt->month = 1