Registration

create_function($s1,$s2) creates an anonymous function and returns a unique name for it. $s1 is the arguments string while $s2 contains the function code.

RESETRUNFULL
<!DOCTYPE html><html><head></head>
<body><?php

$f = create_function('$a,$b','echo $a.$b;');
$f('Hello',' World');

?></body></html>
register_shutdown_function($s[,$m……]) registers a callback function $s to be executed after the script execution finishes or exit() is called.

RESETRUNFULL
<!DOCTYPE html><html><head></head>
<body><?php
function shout($s){echo "$s!";}
function laugh($s){echo "$s!";}
register_shutdown_function('shout','Bye World');
register_shutdown_function('laugh',' Haha');
?></body></html>