Nested Structure in C

Nested Structure in C

• Nested structure in c language can have another structure as a member. There are two ways to define nested structure in c language:

Nested Structure

1. By separate structure
2. By Embedded structure

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1) Separate structure

• We can create 2 structures, but dependent structure should be used inside the main structure as a member. Let's see the code of nested structure.

struct Date  

{  

   int dd;  

   int mm;  

   int yyyy;   

};  

struct Employee  

{     

   int id;  

   char name[20];  

   struct Date doj;  

}emp1;

• As you can see, doj (date of joining) is the variable of type Date. Here doj is used as a member in Employee structure. In this way, we can use Date structure in many structures.

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2) Embedded structure

• We can define structure within the structure also. It requires less code than previous way. But it can't be used in many structures.

struct Employee  

{     

   int id;  

   char name[20];  

   struct Date  

    {  

      int dd;  

      int mm;  

      int yyyy;   

    }doj;  

}emp1;

Accessing Nested Structure

• We can access the member of nested structure by Outer_Structure.Nested_Structure.member as given below:

e1.doj.dd  

e1.doj.mm  

e1.doj.yyyy 

C Nested Structure example

Let's see a simple example of nested structure in C language.

#include <stdio.h>  

#include <string.h>  

struct Employee  

{     

   int id;  

   char name[20];  

   struct Date  

    {  

      int dd;  

      int mm;  

      int yyyy;   

    }doj;  

}e1;  

int main( )  

{  

   //storing employee information  

   e1.id=101;  

   strcpy(e1.name, "Manjeet Singh Kuthar");//copying string into char array  

   e1.doj.dd=10;  

   e1.doj.mm=11;  

   e1.doj.yyyy=2014;  

  

   //printing first employee information  

   printf( "employee id : %d\n", e1.id);  

   printf( "employee name : %s\n", e1.name);  

   printf( "employee date of joining (dd/mm/yyyy) : %d/%d/%d\n", e1.doj.dd,e1.doj.mm,e1.doj.yyyy);  

   return 0;  

} 

Output:

employee id : 101

employee name : Manjeet Singh Kuthar

employee date of joining (dd/mm/yyyy) : 10/07/2010