Reverse byte order using union, How?

[jbp2004]

Hello !

Now, I am able to get reverse byte order using the following function:

void GetReverseHexa(int n) {
	int a, b, c, d, e;
	a = n & 0x000000FF;
	b = n & 0x0000FF00;
	c = n & 0x00FF0000;
	d = n & 0xFF000000;

	a <<= 24;
	b <<= 8;
	c >>= 8;
	d >>=24;

	e = a|b|c|d;

	printf("\nReverse byte order: %2x\n\n",e);
}

parameter n is the given number (user input). Now, the task it to come up with the same output but using union. Anyone who has an idea?