- var_dump: documentation ( source)
- preg_match: documentation ( source)
<?php
$s = '<iframe ><embed width=222>fdgwidth=700dfg</embed>sfsdfsdf</iframe>';
$matches = array();
var_dump( preg_match('~<[^>]+\swidth=["\']?(\d+)["\']?[^>]*>~', $s, $matshes) );
var_dump($matshes);