- preg_match_all: documentation ( source)
<?php
$test= 2;
$asd = "http://gogle.com/999/03/19/1988";
preg_match_all('^\d+/\d+/\d+^',$asd,$matches,PREG_PATTERN_ORDER);
$arraylen = count($matches[0]);
if(0 < $arraylen){
echo intval($matches[0][$arraylen-1]);
}else{
echo -1;
}