PHP Regular Expression character encoding representation

str = ' People's Republic of China 123456789ABCDEFG ';

Echo Preg_match ("/^[\u4e00-\u9fa5_a-za-z0-9]{3,15}", StrName);

Run the code above to see what prompts?

Warning:preg_match (): compilation Failed:pcre does not support \l, \l, \ n, \p, \p, \u, \u, or \x at offset 3 in F:\wwwro Ot\php\test.php on line 2

Originally, the following Perl escape sequences are not supported in PHP regular expressions: \l, \l, \ n, \p, \p, \u, \u, or \x

In UTF-8 mode, "\x{...}" is allowed, and the content in curly braces is a string that represents a hexadecimal number. The original hexadecimal escape sequence, \xhh, matches a double-byte UTF-8 character if its value is greater than 127.

So, you can solve Preg_match ("/^[\x80-\xff_a-za-z0-9]{3,15}", StrName);