关于正则的简单问题

^a 表示以a 开头

[^a]表示除了a的任何字符

[a-zA-Z] a 到 z 或 A 到 Z，两头的字母包括在内（范围）

java doc文档里 Pattern 类里面有详细的介绍

^a就表示以a开头

LZ的E文不知如何,下面就是JAVASCRIPT的全部解释,其它语言的正则表达式也类似.

Character Meaning
\ For characters that are usually treated literally, indicates that the next character is special and not to be interpreted literally. For example, /b/ matches the character 'b'. By placing a backslash in front of b, that is by using /\b/, the character becomes special to mean match a word boundary.-or-For characters that are usually treated specially, indicates that the next character is not special and should be interpreted literally. For example, * is a special character that means 0 or more occurrences of the preceding character should be matched; for example, /a*/ means match 0 or more a's. To match * literally, precede the it with a backslash; for example, /a\*/ matches 'a*'.
^ Matches beginning of input or line.F