PHP: How do you determine every Nth iteration of a loop?

Question

I wanted to echo an image every after 3 post via XML here is my code :

Answer 1

The easiest way is to use the modulus division operator.

if ($counter % 3 == 0) {
   echo 'image file';
}

How this works: Modulus division returns the remainder. The remainder is always equal to 0 when you are at an even multiple.

There is one catch: 0 % 3 is equal to 0. This could result in unexpected results if your counter starts at 0.