Windows版本的PHP具有对该扩展的内置支持。您无需加载任何其他扩展即可使用这些功能 此扩展提供的功能根据当前语言环境检查字符或字符串是否属于某个字符类 * [ctype\_alnum](https://www.php.net/manual/en/function.ctype-alnum.php)—检查字母数字字符 * [ctype\_alpha](https://www.php.net/manual/en/function.ctype-alpha.php)—检查字母字符 * [ctype\_cntrl](https://www.php.net/manual/en/function.ctype-cntrl.php)—检查控制字符 * [ctype\_digit](https://www.php.net/manual/en/function.ctype-digit.php)—检查数字字符 * [ctype\_graph](https://www.php.net/manual/en/function.ctype-graph.php)—检查除空格以外的任何可打印字符 * [ctype\_lower](https://www.php.net/manual/en/function.ctype-lower.php)—检查小写字符 * [ctype\_print](https://www.php.net/manual/en/function.ctype-print.php)—检查可打印字符 * [ctype\_punct](https://www.php.net/manual/en/function.ctype-punct.php)—检查是否有任何非空格或字母数字字符的可打印字符 * [ctype\_space](https://www.php.net/manual/en/function.ctype-space.php)—检查空格字符 * [ctype\_upper](https://www.php.net/manual/en/function.ctype-upper.php)—检查大写字符 * [ctype\_xdigit](https://www.php.net/manual/en/function.ctype-xdigit.php)—检查表示一个十六进制数字的字符