If the structure is nested inside a union, it is called as a union of structures. There is a possibility to create a union inside a structure in C programming language.
Example
Following is the C program for union of structures −
#include<stdio.h>
struct x {
int a;
float b;
};
union z{
struct x s;
};
main ( ){
union z u;
u.s.a = 10;
u.s.b = 30.5;
printf("a=%d", u.s.a);
printf("b=%f", u.s.b);
getch ( );
}Output
When the above program is executed, it produces the following result −
a= 10 b = 30.5
Example
Given below is another C program for union of structures −
#include<stdio.h>
union abc{
int a;
char b;
}v;
int main(){
v.a=90;
union abc *p=&v;
printf("a=%d\n",v.a);//90
printf("b=%c\n",v.b);//Z
printf("a=%d b=%c\n",p->a,p->b);//90 Z
printf("%d",sizeof(union abc));//4
return 0;
}Output
When the above program is executed, it produces the following result −
a=90 b=Z a=90 b=Z 4