Regular expression syntax summary

Here are some basic elements of regular expressions in C#.

.
Match any character except a newline.
[…]
Match any of a set of characters. Characters may be listed individually; for example, [ace] will match the characters 'a', 'c', or 'e'. A set may also contain character ranges; for example, [0-9a-dA-D] will match any decimal digit, the lowercase characters from 'a' to 'd', or the uppercase characters from 'A' to 'D'.
[^…]
Match any character that is not in the given set.
\b
Match a word boundary between an alphanumeric and non-alphanumeric character.
\d
Match any decimal digit.
\s
Match any whitespace character.
\w
Match any alphanumeric character, including underscores.
^
Anchor to the start of the source string.
$
Anchor to the end of the source string.
*
Match 0 or more repetitions of the preceding expression.
+
Match 1 or more repetitions of the preceding expression.
?
Match 0 or 1 repetitions of the preceding expression.
expr1 | expr2
Matches either expr1 or expr2.
(…)
Indicates the start and end of a group.
(?i)
Enable case-insensitive matching.
(?x)
Ignore unescaped whitespace in the regular expression pattern.