Expert: Narendra - 8/24/2006

Question
Hi,
Can u explain me the output of the following code?

#include <stdio.h>
void main ()
{
union {
int i;
float f;
char ch[5];
}u;
printf ("Value of float %f, %u\n", u.f, &u.f);
}

If I read float in the above union what is the output?
Output is:0.000000 and its address.
But how and why?  

Answer
For any variable (except global variables), the value is undefined when it is defined.
You must initialize it before using.
So, I cannot tell anything about the o/p, since you are dealing with an undefined (sometimes called garbage) value.
The same may give different o/p on different computers!