unexpected output in C (recursion)

Question

int main(void) {
 static int=5;
 if(--i) {
    main();
    printf(\"%d\",i);
   }
 }

the output of above program is---

0000

But I t

Answer 1

1. You set a static variable i to 5
2. You recurse on main until i becomes zero.
3. The recursion unwinds with i being zero.
4. This then calls the printf

There lies the answer.

You can prove this by using a debugger

Answer 2

  [First call:  i->4 and call main()]
  [Second call: i->3 and call main()]
  [Third call:  i->2 and call main()]
  [Fourth call: i->1 and call main()]
  [Fifth call:  i->0 and condition false as it gives 0.]

Now it's time for the printing of value of i, which was the next line after main(). Control go back to fourth to first call to print value of i.

[Fourth Call: printing value of i which is 0.]
[Third call:  printing value of i which is 0.]
[Second call: printing value of i which is 0.]
[First call:  printing value of i which is 0.]

Answer 3

The reason for the zeros is that i is decremented down to zero before the very first printf statement is run. As it unwinds, it prints i (which is still zero) each time.

It would be better to use a separate function that main() calls and passes a parameter to (and then pass the parameter to each call rather than using a static variable).