php 将字符串按大写字母分隔成字符串数组

<?php
$str="abcDefGhi";
/*
preg_match_all("/([a-zA-Z]{1}[a-z]*)?[^A-Z]/",$str,$array);
*/
$array=preg_split("/(?=[A-Z])/",$str);
print_r($array);
?>

<?php
$string = "createTechBook";
$arr = preg_split("/(?=[A-Z])/", $string);
print_r($arr);
?>