Function inside structure in C code example

Example 1: structure and function in c

#include <stdio.h>
#include <string.h>
 
struct student 
{
           int id;
           char name[20];
           float percentage;
};
 
void func(struct student *record);
 
int main() 
{
          struct student record;
 
          record.id=1;
          strcpy(record.name, "Raju");
          record.percentage = 86.5;
 
          func(&record);
          return 0;
}
 
void func(struct student *record)
{
          printf(" Id is: %d \n", record->id);
          printf(" Name is: %s \n", record->name);
          printf(" Percentage is: %f \n", record->percentage);
}

Example 2: function inside struct c

typedef struct client_t client_t, *pno;
struct client_t
{
        pid_t pid;
        char password[TAM_MAX]; // -> 50 chars
        pno next;

        pno (*AddClient)(client_t *);  <-- pointer to function    
};

pno client_t_AddClient(client_t *self) { /* code */ } <-- function

int main()
{

    client_t client;
    client.AddClient = client_t_AddClient; // probably really done in some init fn

    //code ..

    client.AddClient(&client);

}

Example 3: structure and function in c

#include <stdio.h>
#include <string.h>
 
struct student 
{
            int id;
            char name[20];
            float percentage;
};
 
void func(struct student record);
 
int main() 
{
            struct student record;
 
            record.id=1;
            strcpy(record.name, "Raju");
            record.percentage = 86.5;
 
            func(record);
            return 0;
}
 
void func(struct student record)
{
            printf(" Id is: %d \n", record.id);
            printf(" Name is: %s \n", record.name);
            printf(" Percentage is: %f \n", record.percentage);
}