Verschachtelte Struktur Verwendung in C

Question

Aus dem folgenden Snippet.

  typedef struct { 
       int Code; 
       int ParentCode; 
      }TypeStudentConfidential; 

      typedef struct { 
       int age; 
       int RollNo; 
       int Rank; 
       char Name[10]; 
      }TypeStudent; 

      typedef struct { 
       char class_name[20]; 
       //XXXXXXXXXXXXXXXXX //How could I declare the TypeClass element here? 
      }TypeClass; 

      int main() 
      { 

       const TypeStudent Stu_Details[] = { 
       { 3, 1, 18, "Mahesh"}, 
       { 3, 1, 7, "Kumar"} 
       }; 

       const TypeStudentConfidential Conf_Details[] = { 
       { 761, 814}, 
       { 124, 562} 
       }; 

       const TypeClass Class_Details[]= { 
       { "Class 10",  Stu_Details}, //struct TypeStudent data 
       { "Class 8",  Conf_Details} //struct TypeStudentConfidential data 
       }; 

       return 0; 
      } 

Fragen:

1) Wie die XXXXXX markiert typedef struct Element

2) zu definieren, wie die von XXXXXX markierte Element Class_Details zuzugreifen

Answer 1

typedef struct TypeClass { 
    char class_name[20]; 
    struct TypeStudent* type; 
} TypeClass; 

und

Typeclass a = {"classA", NULL}; 
Typeclass b = {"classB", NULL}; 
a.type = &b; 
printf("%s\n", a.type->class_name); //prints b's classname 

Jetzt zugreifen, wenn Sie XXXXXXXXXX wollen entweder ein TypeStudent OR TypeStudentConfidential (wie Ihr Code snippit scheint darauf hinzudeuten) Sie werden wahrscheinlich eine union, wie so verwenden müssen sein:

#include <stdio.h> 


typedef struct TypeClass{ 
     char class_name[20]; 
     union type { 
       struct TypeStudent* students; 
       struct TypeStudentConfidential* studentConfs; 
     } type; 
} TypeClass; 

typedef struct TypeStudent { 
     int age; 
     int RollNo; 
     int Rank; 
     char Name[10]; 
} TypeStudent; 

typedef struct TypeStudentConfidential { 
     int Code; 
     int ParentCode; 
} TypeStudentConfidential; 

int main() { 
     //TypeClass a[2] = {{"C0", {NULL}}, {"C1", {NULL}}}; 

     TypeStudent studs[2] = {{10, 10, 10, "Joe"}, {5, 5, 5, "Bob"}}; 
     TypeStudentConfidential confs[2] = {{1, 2}, {3, 4}}; 

     TypeClass a[2] = {{"C0", {.students = studs}}, {"C1", {.studentConfs = confs}}}; 

     //a[0].type.students = studs; 
     //a[1].type.studentConfs = confs; 

     printf("%s, %s\n", a[0].type.students->Name, (a[0].type.students + 1)->Name); 
     printf("%i, %i\n", a[1].type.studentConfs->Code, (a[1].type.studentConfs + 1)->Code); 
     return 0; 
}