For a complete list of character classes , see appendix b of the xml specification 有关字符类的完整列表,请参阅xml规范的附录b 。
A quantifier expression applies to the character , group , or character class that immediately precedes it 限定符表达式应用于紧挨着它前面的字符、组或字符类。
You can specify a character class , by enclosing a list of characters in [ ] , which will match any one character from the list 你可以通过用[ ]包括一系列字符指定一个字符类,将匹配任何[ ]中的字符。