- print_r: documentation ( source)
- preg_replace: documentation ( source)
<?php
$amount = 5;
$stuff = '<div><div class="rev_slider_2_2_wrapper"></div><i id="rev_slider_2_2_wrapper"></i></div>';
preg_replace( '~rev_slider_([\d]*)_([\d]*)_wrapper~ui', $stuff, $amount );
print_r( $stuff );