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

Use the modulo arithmetic operation found here in the PHP manual.

e.g.

$x = 3;

for($i=0; $i<10; $i++)
{
    if($i % $x == 0)
    {
        // display image
    }
}

For a more detailed understanding of modulus calculations, click here.