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Declaration of a union variable in C

Union variable can be declared while defining a union or after defining a union.

Let us see how to declare a union variable while defining a union.
union book {
          char name[32];
          int price;
}obj;

Here, obj is a union variable of type union book and it is declared while defining the union book.

Let us see how to declare a union variable after defining a union.
union book {
          char name[32];
          int price;
};

union book obj1, obj2;

Here, obj1 and obj2 are union variables of type union book.  And they are declared after defining the union book.

Union variable declaration example in C

  #include <stdio.h>
#include <string.h>
union book {
char name[32];
int price;
}obj1; // union variable declaration at definition

union book obj2; // union variable declaration after definition

int main() {
strcpy(obj1.name, "Davinci code");
printf("obj1.name: %s\n", obj1.name);
strcpy(obj2.name, "Twilight");
printf("obj2.name: %s\n", obj2.name);
return 0;
}

  Output:
  jp@jp-VirtualBox:~/$ ./a.out
  obj1.name: Davinci code
  obj2.name: Twilight




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