Character

Description

\

Marks the next character as either a special character or
escapes a literal. For example, "n" matches the character
"n". "\n" matches a newline character. The sequence
"\\" matches "\" and "\(" matches
"(".

Note: double quotes may be escaped by doubling them:
"<a href=""...>"


^

Depending on whether the MultiLine option is set, matches the
position before the first character in a line, or the first character in the
string.

$

Depending on whether the MultiLine option is set, matches the
position after the last character in a line, or the last character in the
string.

*

Matches the preceding character zero or more times. For
example, "zo*" matches either "z" or "zoo".

+

Matches the preceding character one or more times. For
example, "zo+" matches "zoo" but not "z".

?

Matches the preceding character zero or one time. For example,
"a?ve?" matches the "ve" in "never".

.

Matches any single character except a newline character.

(pattern)

Matches pattern and remembers the match. The
matched substring can be retrieved from the resulting Matchescollection,
using Item [0]...[n]. To match parentheses characters ( ), use
"\(" or "\)".

(?<name>pattern)

Matches pattern and gives the match a name.

(?:pattern)

A noncapturing group

(?=...)

A positive lookahead

(?!...)

A negative lookahead

(?<=...)

A positive lookbehind .

(?<!...)

A negative lookbehind .

xy

Matches either x or y. For
example, "zwood" matches "z" or "wood".
"(zw)oo" matches "zoo" or "wood".

{n}

n is a nonnegative integer. Matches exactly n times.
For example, "o{2}" does not match the "o" in
"Bob," but matches the first two o's in "foooood".

{n,}

n is a nonnegative integer. Matches at least n times.
For example, "o{2,}" does not match the "o" in
"Bob" and matches all the o's in "foooood."
"o{1,}" is equivalent to "o+". "o{0,}" is
equivalent to "o*".

{n,m}

m and n are nonnegative integers.
Matches at least n and at most m times. For
example, "o{1,3}" matches the first three o's in
"fooooood." "o{0,1}" is equivalent to "o?".

[xyz]

A character set. Matches any one of the enclosed characters.
For example, "[abc]" matches the "a" in
"plain".

[^xyz]

A negative character set. Matches any character not enclosed.
For example, "[^abc]" matches the "p" in
"plain".

[az]

A range of characters. Matches any character in the specified
range. For example, "[az]" matches any lowercase alphabetic
character in the range "a" through "z".

[^mz]

A negative range characters. Matches any character not in the
specified range. For example, "[mz]" matches any character not in
the range "m" through "z".

\b

Matches a word boundary, that is, the position between a word
and a space. For example, "er\b" matches the "er" in
"never" but not the "er" in "verb".

\B

Matches a nonword boundary. "ea*r\B" matches the
"ear" in "never early".

\d

Matches a digit character. Equivalent to [09].

\D

Matches a nondigit character. Equivalent to [^09].

\f

Matches a formfeed character.

\k

A backreference to a named group.

\n

Matches a newline character.

\r

Matches a carriage return character.

\s

Matches any white space including space, tab, formfeed, etc.
Equivalent to "[ \f\n\r\t\v]".

\S

Matches any nonwhite space character. Equivalent to
"[^ \f\n\r\t\v]".

\t

Matches a tab character.

\v

Matches a vertical tab character.

\w

Matches any word character including underscore. Equivalent to
"[AZaz09_]".

\W

Matches any nonword character. Equivalent to
"[^AZaz09_]".

\num

Matches num, where num is a
positive integer. A reference back to remembered matches. For example,
"(.)\1" matches two consecutive identical characters.

\n

Matches n, where n is an octal
escape value. Octal escape values must be 1, 2, or 3 digits long. For
example, "\11" and "\011" both match a tab character.
"\0011" is the equivalent of "\001" & "1".
Octal escape values must not exceed 256. If they do, only the first two
digits comprise the expression. Allows ASCII codes to be used in regular
expressions.

\xn

Matches n, where n is a
hexadecimal escape value. Hexadecimal escape values must be exactly two
digits long. For example, "\x41" matches "A".
"\x041" is equivalent to "\x04" & "1".
Allows ASCII codes to be used in regular expressions.

\un

Matches a Unicode character expressed in hexadecimal notation
with exactly four numeric digits. "\u0200" matches a space
character.

\A

Matches the position before the first character in a string.
Not affected by the MultiLine setting

\Z

Matches the position after the last character of a string. Not
affected by the MultiLine setting.

\G

Specifies that the matches must be consecutive, without any
intervening nonmatching characters.

C#.Net Regular Expression Cheat Sheet Reference
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