Solve and explain the answer i did not understand what's going on?

Question

#include<stdio.h>
#include<conio.h>

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

Answer 1

firstly. conio.h
no, just don't.. unless you're a time traveller that is, if so Welcome to the 21st century!
https://en.m.wikipedia.org/wiki/Conio.h

secondly printf; I assume this is where your confusion lay. try reading through this reference information, it may help.
http://www.cplusplus.com/reference/cstdio/printf/

also here is information on prefix/postfix operators.
http://en.cppreference.com/w/cpp/language/operator_incdec