Groovy正則表示式
阿新 • • 發佈：2019-02-18
Regular expressions are the Swiss Army knife of text processing. They provide the programmer the ability to match and extract patterns from strings. The simplest example of a regular expression is a string of letters and numbers. And the simplest expression involving a regular expression uses the ==~
Regular Expression Operators| a? | matches 0 or 1 occurrence of *a* | 'a' or empty string |
|---|---|---|
| a* | matches 0 or more occurrences of *a* | empty string or 'a', 'aa', 'aaa', etc |
| a+ | matches 1 or more occurrences of *a* | 'a', 'aa', 'aaa', etc |
| a|b | match *a* or *b* | 'a' or 'b' - |
| . | match any single character | 'a', 'q', 'l', '_', '+', etc |
| [woeirjsd] | match any of the named characters | 'w', 'o', 'e', 'i', 'r', 'j', 's', 'd' |
| [1-9] | match any of the characters in the range | '1', '2', '3', '4', '5', '6', '7', '8', '9' |
| [^13579] | match any characters not named | even digits, or any other character |
| (ie) | group an expression (for use with other operators) | 'ie' |
| ^a | match an *a* at the beginning of a line | 'a' |
| a$ | match an *a* at the end of a line | 'a' |
There are a couple of other things you should know. If you want to use one of the operators above to
mean the actual character, like you want to match a question mark, you need to put a '/' in front of it.
For example: