Structure within structure in C

 A structure nested inside another structure is called structure within structure.

Method1:

struct velocity {

     char name[100];

     int distance;

     struct time_taken {

               int hours;

               int minutes;

               int seconds;

     } tobj;

} vobj;

Method 2:

struct time_taken {

          int hours;

          int minutes;

          int seconds;

};

struct velocity {

          char name[100];

          int distance;

          struct time_taken tobj;

}vobj;

Ways to access data members of the inner structure:

vobj.tobj.hours = 12

vobj.tobj.minutes = 30

Nested structure example in C:

  #include <stdio.h>
  struct time_taken {
        int hours;
        int minutes;
        int seconds;
  };

  struct velocity {
        char name[100];
        int distance;
        struct time_taken tm;
  };

  int main() {
        struct velocity v1 = {"ram", 7200, {10, 0, 0}};
        int velocity_op;
        int time = (((v1.tm.hours) * 3600) +
                        ((v1.tm.minutes) * 60) + (v1.tm.seconds));
        velocity_op = (v1.distance * 1000) / time;
        printf("Velocity:%dm/sec\n", velocity_op);
        return 0;
 }

  Output:

  jp@jp-VirtualBox:~/$ ./a.out
  Velocity:200m/sec