There are many figures that need to be specially processed when trying to match them. To match these special characters, these characters must first use these characters, that is, use a backslash (/) in front. The following table gives these special characters and its meaning:
Special character descriptions $ Match the end position of the input string. If the demiline property of the Regexp object is set, $ or '/ r' is matched. To match the worth itself, use / $. () Mark the beginning and end position of a child expression. Sub-expressions can be used later. To match these characters, use / (and /). * Match the previous sub-expression zero or multiple times. To match * characters, use / *. Match the previous sub-expression once or multiple times. To match characters, use / . Matches any single characters other than the resort / N. To match., Please use /. [Marking a bracket expression. To match [, please use / [. • Match the previous sub-expression zero or once, or indicate a non-greedy qualifier. To match? Characters, please use / ?. / Tag the next character as a special character, or primary character, or backward reference, or eight-way escape. For example, 'n' matches character 'n'. '/ n' matches changing. Sequence '//' Match "/", and '/ (', match "(". ^ Matches the start position of the input string unless used in square brackets, it indicates that it does not accept the character set. Match ^ Character itself, please use / ^. {Tag qualifier expression. To match {, please use / {. | Indicate two options. To match |, please use / |.
