For Using C Unions on a Raspberry Pi -> https://www.youtube.com/watch?v=Q-uwhWtfy2I

Union.c

#include <stdio.h>

union
{
   unsigned int i;
   unsigned char c;
} aunion;

int main()
{
   aunion.i = 42;

   printf("The answers are %d and %c\nWhy is that?\n", aunion.i, aunion.c);
   printf("Unions are a facinating way of manipulating memory content\n");
   printf("But can be dangerous, which is why you will not find them in Java\n");
   printf("What is happening with the union 'aunion'?\n\n");
   
   printf("And like the last video, this is fast to compile\n");
   printf("But with Java you can take the .class file and run it on anything\n");
   printf("with a a Java Virtual Machine.\n");
   
   return aunion.i;
}