Regular Expression Formatting

Pattern	Description
Constant Escape Characters
\a	This matches the bell character: \u0007. For example, it matches "Test" + '\u0007'
\b	This matches the backspace character: \u0008. For example, it matches "Test" + '\u0008'
\t	This matches the tab character: \u0009. For example, it matches "Test" + '\u0009'
\n	This matches the newline character: \u000A. For example, it matches "Test" + '\u000A'
\v	This matches the vertical tab character: \u000B. For example, it matches "Test" + '\u000B'
\f	This matches the form feed character: \u000C. For example, it matches "Test" + '\u000C'
\r	This matches the carriage return character: \u000D. For example, it matches "Test" + '\u000D'
\e	This matches the escape character: \u001B. For example, it matches "Test" + '\u001B'
Variable Escape Characters
\cA	This matches the Ctrl-A character for an ASCII character.
\ooo	This matches the ASCII character with the octal value ooo.
\xhh	This matches the ASCII character with the hexadecimal value hh.
\uhhhh	This matches the Unicode character with the hexadecimal value hhhh.
Character Classes
.	This matches any single character, except newline and carriage return. It is used as a placeholder. So, the pattern fa.e matches "face", "fade", "fare", "fate", "fake", or "fame"
x..x	This matches anything with an "x" at each end and two characters in between; for example, it matches "xoax" or "xslx".
\w	This matches any word character.
\W	This matches any non-word character.
\d	This matches any decimal digit character.
\D	This matches any character that is not a decimal digit.
\s	This matches any white-space character.
\S	This matches any non-white-space character.
[...]	This matches any character inside the brackets. For example, [dox] matches "d", "o", or "x".
[az]	This matches any "a" or "z" character. For example, it matches the second and third characters of "raze" for the "a" and "z" at those locations.
fa[cdr]e	This matches the patterns "face", "fade" and "fare".
[^...]	This matches any character that is not inside the brackets. For example, [^dox] matches anything except "d", "o", or "x".
http[^s]	This matches any "http" this is not followed by an "s". So, it matches the beginning of "http://xoax.net/", but not "https://xoax.net/".
[First-Last]	This matches any character from "First" to "Last", inclusive. For example, [r-x] matches "r", "s", ..., "x".
[^First-Last]	This matches any character, except from "First" to "Last", inclusive. For example, [^r-x] matches anything except "r", "s", ..., "x".
\p{unicode category}	This matches any character in the unicode category.
\P{unicode category}	This matches any character that is not in the unicode category.
Quantifiers
*	This matches the preceding element zero or more times.
x..x.*	This matches anything with an "x" followed by any two characters and then an "x"; for example, it matches "xoax" or "xoax.net", but not "xox" or "xoa".
+	This matches the preceding element one or more times.
x..x.+	This matches anything with an "x" followed by any two characters and then an "x" and one or more characters; for example, it matches "xoaxn" or "xoax.net", but not "xoax".
?	This matches the preceding element zero or one time.
x..x.?	This matches anything with an "x" followed by any two characters and then an "x" and at most one more character; for example, it matches "xoax" or "xoax.", but not "xoax.net".
{n}	This matches the preceding element n times.
{n,}	This matches the preceding element at least n times.
{n,m}	This matches the preceding element at least n times but no more than m times.
Anchors
^	This must match the first position of a string or the first position of any line.
^cat	This matches the beginning of a string or line that begins with "cat", such as "category" but not "decathlon".
$	This must match the last position of a string or the last position of any line.
cat$	This matches the end of a string or line that ends with "cat", such as "requiescat" or "magnificat" but not "desiccated".
\A	This must match the start of a string.
\Z	This must match the end of a line, just before a newline.
\z	This must match the end of a string.
\G	This must match where a previous match ended.
\b	This must match on the boundary between an alphanumeric and a nonalphanumeric character.
\B	This must match on somewhere other than the boundary between an alphanumeric and a nonalphanumeric character.
Groups
(subexpression)	This captures the matched subexpression as a group and assigns it a one-based index.
(?<name>subexpression) or (?'name'subexpression)	This captures the matched subexpression as a group and assigns it to name.
(?<name1-name2>subexpression) or (?'name1-name2'subexpression)	This defines a balancing group definition.
(?:subexpression)	This defines a noncapturing group.
(?imnsx-imnsx:subexpression)	This applies or disables the specified options within the subexpression.
(?=subexpression)	This defines a zero-width positive lookahead assertion.
(?!subexpression)	This defines a zero-width negative lookahead assertion.
(?<=subexpression)	This defines a zero-width positive lookbehind assertion.
(?<!subexpression)	This defines a zero-width negative lookbehind assertion.
(?>subexpression)	This defines an atomic group.