Pointers to Structures
You can define pointers to structures in the same way as you define pointer to any other variable:
struct Books *struct_pointer;
Now, you can store the address of a structure variable in the above-defined
pointer variable. To find the address of a structure variable, place the ‘&’operator before the structure's name as follows:
struct_pointer = &Book1;
To access the members of a structure using a pointer to that structure, you must use the -> operator as follows:
struct_pointer->title;
Let us rewrite the above example using structure pointer.
#include <stdio.h>
#include <string.h>
struct Books
{
char title[50];
char author[50];
char subject[100];
int book_id;
};
/* function declaration */
void printBook( struct Books *book );
int main( )
{
struct Books Book1; /* Declare Book1 of type Book */
struct Books Book2; /* Declare Book2 of type Book */
/* book 1 specification */
strcpy( Book1.title, "C Programming");
strcpy( Book1.author, "Nuha Ali");
strcpy( Book1.subject, "C Programming Tutorial");
Book1.book_id = 6495407;
/* book 2 specification */
strcpy( Book2.title, "Telecom Billing");
strcpy( Book2.author, "Zara Ali");
strcpy( Book2.subject, "Telecom Billing Tutorial");
Book2.book_id = 6495700;
/* print Book1 info by passing address of Book1 */
printBook( &Book1 );
/* print Book2 info by passing address of Book2 */
printBook( &Book2 );
return 0;
}
void printBook( struct Books *book )
{
printf( "Book title : %s\n", book->title);
printf( "Book author : %s\n", book->author);
printf( "Book subject : %s\n", book->subject);
printf( "Book book_id : %d\n", book->book_id);
}
When the above code is compiled and executed, it produces the following result:
Book title : C Programming
Book author : Nuha Ali
Book subject : C Programming Tutorial
Book book_id : 6495407
Book title : Telecom Billing
Book author : Zara Ali
Book subject : Telecom Billing Tutorial
Book book_id : 6495700
Note :- Above information taken from tutorial point book.