Use of typedef with structures

typedef gives a new name to an existing data type. With a structure, it lets us declare variables without writing the keyword struct each time, which shortens the code.

typedef struct student {
    char name[20];
    int roll;
} Student;

Student s1, s2;     /* instead of: struct student s1, s2; */

Here Student is the new type name (not a variable). The tag student is optional; it can be left out, as in the program below.

#include <stdio.h>

typedef struct {
    char name[20];
    int roll;
} Student;               /* Student is now a type name */

int main(void)
{
    Student s = {"Ram", 7};          /* no 'struct' keyword needed */
    printf("%s %d\n", s.name, s.roll);
    return 0;
}

Output: Ram 7