源码：
@header("content-Type: text/html; charset=utf-8");
$demon = 'm.sbmmt.com';
$Chinese = 'PHP中文网';
echo strlen($demon),'<hr>';
echo strlen($Chinese),'<hr>';
echo mb_strlen($demon),'<hr>';
echo mb_strlen($Chinese),'<hr>';
echo mb_strwidth($demon),'<hr>';
echo mb_strwidth($Chinese),'<hr>';
输出：
10
12
10
12##%
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
