C:UNION

You can store only one value at any given location at any given time. By using the unions, you can interpret the contents of that location differently.
Eg:
union {
short s1;
char xyz[sizeof(short)];
}my_union;

you can store some value in
my_union.s1 = 0x0102; // a numeric value in Hex

u can see the contents of same location as 'chars' by
my_union.xyz[0], my_union.xyz[1]
Regards
rk

Yes.. Probably I did not understand your question.
Here is a sample pgm...
union {
char x[20];
char y[10];
}u1;
memset((void *) &u1,0, sizeof (u1));
strcpy (u1.x,"ABCDEFGHIJKLMNOPQRST");
printf("before initialization\n");
printf("\nx: %s\n", u1.x);
printf("\ny: %s\n", u1.y);
memset(&u1.y[0],' ',10);
printf("after initialization\n");
printf("\nx: %s\n", u1.x);
printf("\ny: %s\n", u1.y);

Results are:
before initialization
x: ABCDEFGHIJKLMNOPQRST
y: ABCDEFGHIJKLMNOPQRST
after initialization
x: KLMNOPQRST
y: KLMNOPQRST

Please see if this answers the question if not please state it again.
Thanks & Rgds
rk

hi,
First of all let me admit that i didn't understand ur question properly. Even than i will try.

First of all you cannot store two different thing in the same memory location. But u can use union to store different values but that won't be in the same memory location.

For example if you want to store an int and a char in the union than u can do it in the following manner.

union
{
int a[2];
char c;
};

In this case a[0] and c will be overlapping. (This clearly depends on the byte ordering used by the processor. It can be the other ways round also.) Now in the union a[1] can be used to store an int and c can be used to store char.

Let be frank with u. This is not why union are meant for. U can use a structure instead. Union is mainly used to interpret same data in different manners.
I will give u an eg.
suppose u have four characters. Now ur requirment is that u have combine these four chars to form a long int. This thing can be easily by using an union. (Although there are many other ways to do this.)
union
{
char c[4];
long l;
}

Now whenever u want the char use union.c[] and when u want them to be interpreted as long than use union.l .

I hope ur doubt is cleared. If not than pls mention ur doubt in detail.