passing a function results as argument to other function

<?php
$string="0:1027301|pe_id:1027301|1:ko ben|NAME:ko
 ben|2:0555532963|PHONE2:0555532963|3:07711111|PHONE1:07711111|";

echo $value=preg_replace('/[^0-9]+/', '', stristr(stristr($string, 'PHONE2'),'|',true));

?>
 we use 3 functions  (  2 times stristr()  and preg_replace()

search value of PHONE2:0555532963