文档介绍：正贝!l表达式定义(Regular expression definition) 3. regular expression definition
Regular expressions (regular expression) descaracter description
$matches the end of the input string. If the Multiline property of the RegExp object is set, then $matches' \n' or' \r' . To match the $character itself, please use the \ $,
(mark) the start and end positions of a child expression. Sub expressions can be obtained for later use. To match these characters, use \ \ (and \ \).
* matches the previous sub expression zero or more times. To use the character, *.
+ matches the previous sub expression one or more times. To match the + character, please use the \ + acts.
Matches any single character except the newline character \n. To match. Use \ \ \.
[marks the beginning of a bracket expression. Please use the \[[to match.
Matches the previous sub expression zero or twice, or indicates a non greedy qualifier. To match characters, use \ \?.
Mark the next character as either a special character, or a literal character, or a backward reference, or an octal escape character. For example, the' n' matches the character' n'.
, \n，matches newline characters. Sequence matching, and \ \ \ ''\ (match ”(”.
Matches the start position of the input string unless it is used in the square bracket expression. At this point it indicates that the collection of characters is not accepted. To match the ' charac