Advanced Notes (2)--javascript fine crushed

Regular/Regular Expressions/

^ denotes string start

（？ ：... ) represents a non-capturing grouping (not much meaning)

Suffix? Indicates a match 0 or 1 times

（ ... ) represents a capturing type grouping

[^] means beyond []

* Match 0 or more times

+ Match 1 shipments multiple times

[Character class] matches by "character class"

/I is case insensitive

/g Global match

/m multi-line matching

$ match End

Regexp

New a RegExp object that accepts two parameters (one is the string pattern to match and the other is an optional flag string.) Because the schema parameter of the RegExp constructor is a string, in some cases multiple escapes of the character, all metacharacters must be escaped, and those characters that have escaped are also the same) for example:

Literal pattern/\[bc\]at/equivalent string is "\\[bc\\]at"

Regular expression selection: A regular expression contains one or more expressions, with | Separate if matches match one of the expression requirements

Advanced Notes (2)--javascript fine crushed