How structure works in C

struct.c

struct author {
  int age;
  char uname[80];
  char stack[80];
};

struct author new_developer() {
  struct author new;
  printf("Username: ");
  lnrd(new.uname);
  printf("Stack: ");
  lnrd(new.stack);
  return new;
}

void lnrd(char * str) {
  int idx = 0;
  while (true) {
    char ch = getchar();
    if (ch == '\n') 
      break;
    str[idx] = ch;
    idx++;
  }
  str[idx++] = '\0';
}

void pgrd() {
  struct author dev;
  dev = new_developer();
  printf("Developer username: %s\n Stack: %s", dev.uname, dev.stack);
}

void stfn(struct author *dev) {
  printf("age is %i\n", dev->age);
}

int main() {
  struct author dev = {
    22,
    "Jhon",
    "JS"
  },
  *pdev = &dev;
  printf("Username: %s\n", pdev->uname);
  stfn(pdev);
  // pgrd();
  return 0;
}