<?php
$str = "hello world!";
/* 1. won't work with with anonymous inner (lambda) function before PHP 5.3
$str = preg_replace_callback(
'/world/',
function( '$match', 'return "michael";' ),
$str ); */
/* 2. use create_function instead */
$str = preg_replace_callback(
'/world/',
create_function( '$match', 'return "michael";' ),
$str );
echo $str ; // output: hello michael!
?>
