Regular Expression backup

Year:/^ 19/d {2 }$/(20th century)
Month: ^/d {1, 2} $

Character Description:

^ Matches the start of a string. For example:

^ ABC matches "abc xyz" instead of "xyz abc"

$ Symbol matches the end of a string. For example:

ABC $ matches "xyz abc" instead of "abc xyz.

NOTE: If both the ^ and $ symbols are used, exact match is performed. For example:

^ ABC $ only matches "ABC"

* The symbol matches 0 or more characters before it. For example:

AB * can match "AB", "ABB", "abbb", etc.

+ The symbol matches at least one character before it. For example:

AB + can match "ABB", "abbb", but does not match "AB ".

? The symbol matches 0 or 1 character. For example:

AB? C? Only "ABC", "abbc", "ABCC", and "abbcc" can be matched"

The. symbol matches any character except the line break. For example:

(.) + Match all strings except line breaks

X | y matches "X" or "Y ". For example:

ABC | XYZ can match "ABC" or "XYZ", while "AB (c | x) YZ" matches "abcyz" and "abxyz"

{N} matches exactly the characters before n times (N is a non-negative integer. For example:

A {2} can match "AA", but does not match ""

{N,} matches the characters before at least N times (N is a non-negative integer. For example:

A {3,} matches "AAA", "aaaa", but does not match "A" and "AA ".

Note: A {1,} is equivalent to a +

A {0,} is equivalent to *

{M, n} matches at least m characters, and at most n characters are prefixed. For example:

A {1, 3} Only matches "A", "AA", and "AAA ".

Note: A {0, 1} is equivalent to?

[Xyz] indicates a character set that matches one of the characters in brackets. For example:

[ABC] matches "A", "B", and "C"

[^ XYZ] indicates a negative character set. Match any character that does not exist in this bracket. For example:

[^ ABC] can match any character except "A", "B", and "C"

[A-Z] indicates characters in a certain range. It matches any character in a specified range. For example:

[A-Z] matches any lowercase letter character from "A" to "Z"

[^ M-N] indicates a character out of a certain range, matching a character that is not in the specified range. For example:

[M-N] matches any character except "M" to "N"

/Symbols are escape operators. For example:

/N linefeed

/F paging character

/R press ENTER

/T Tab

/V vertical Tab

// Match "/"

// Match "/"

/S any white characters, including spaces, tabs, and pagination characters. It is equivalent to "[/f/n/R/T/V]"

/S any non-blank characters. It is equivalent to "^/f/n/R/T/V]"

/W any word character, including letters and underscores. Equivalent to "[A-Za-z0-9 _]"

/W any non-word characters. Equivalent to "[^ A-Za-z0-9 _]"

/B matches the end of a word. For example:

Ve/B matches the word "love", but does not match "very" or "even ".

/B matches the start of a word. For example:

Ve/B matches the word "very", but does not match "love ".

/D matches a number, which is equivalent to [0-9]. For example:

ABC/dxyz matches "abc2xyz", "abc4xyz", etc,
But does not match "abcaxyz", "ABC-XYZ", etc.

/D matches a non-numeric character, which is equivalent to [^ 0-9]. For example:

ABC/dxyz matches "abcaxyz", "ABC-XYZ", etc,
But does not match "abc2xyz", "abc4xyz", etc.

/Num matches num (where num is a positive integer) and references it back to the remembered match. For example:

(.)/1 matches two consecutive identical characters.

/Onum matches N (where N is an octal value less than 256 ). For example:

/O011 match the tab

/Xnum matches num (Num is a hexadecimal value less than 256 ). For example:

/X41 match the character ""