Introduction to regular expressions in javascript learning notes (11) _ basic knowledge

Introduction to regular expressions in javascript learning notes. For more information, see 1. modifier.
. Any character
* Match * The first 0 or multiple characters
+ Match + the first or more characters
? Matching? First 0 or 1 Character
^ Start with a character after ^
$ Ends with a character before $
[] Match a character in []
() Group, which can be extracted with \ 1 \ 2
[^] Character other than matching ^
There are n characters before {n}, and n is a positive number.
Before {n ,}{ n ,}, there must be at least n characters, and n is a positive number.
The characters before {n, m} {n, m} Are n ~ M, n, m is positive

2. Character
\ D a number
\ D a non-digit
\ W a letter or number
\ W one non-letter and non-digit
\ S a blank character
\ S a non-blank character
\ B word boundary
\ B Non-word boundary

3. Non-Greedy match
+? *? ??