php 编一函数计算一个字符串中有多少个字母.汉字.数字?

<?php
header("Content-type: text/html; charset=utf-8");
echo $str = "43fdf测试fdsfadaf43543543职工问防盗锁防盗锁5345gfdgd";
preg_match_all("/[0-9]{1}/",$str,$arrNum);
preg_match_all("/[a-zA-Z]{1}/",$str,$arrAl);
preg_match_all("/([\x{4e00}-\x{9fa5}]){1}/u",$str,$arrCh);

echo "<pre>";
echo "数字个数:".count($arrNum[0])."<br/>";
echo "字母个数:".count($arrAl[0])."<br/>";
echo "中文个数:".count($arrCh[0]);
?>