What is output of these code and how?

Question

#include <stdio.h>

int main()
{
int i=2;
printf("%d, %d\n", ++i, ++i);
return 0;
}

Answer 1

I checked this code and output is found to be 4,4.
I think this is because comma operator works from left to right. So, the output is twice incremented in both cases.

Answer 2

if you run that

#include <stdio.h>

int main()
{
int i=2;
printf("%d, %d, %d\n", ++i, ++i, i++);
return 0;
}

result is 5,5,2 so the reason of these results is that before to show, compiler run operations ++i as theory said