#define strange

Question

#include<stdio.h>
#include<conio.h>
#define square(v) v*v
void main()
{
int p=3;
int s=square(++p);
printf("%d %d",s,p);
getch();
}

output 25 5 Why 16 4 is not coming as output? (Advance thanks)

Answer 1

A macro is basically a text copy and paste. Therefore your ++ is being duplicated.

The macro is being expanded as:

s = ++p * ++p;

That's the danger of macros. (in this case, it also invokes undefined behavior)