RegExQuickReference.md

Basic Matching

Pattern	Meaning
.	any single character
+	one or more of the preceeding pattern
?	zero or more of the preceeding pattern
\	escape sequence or character class or backreference
[anyofthese]	Any of these characters
[^ *notoneofthese* ]	matches any character that's isnt one of these characters
[start-end]	(matches this range)
^	the begining of the line or string
$	the end of the line or string

Character classes

Instead of writing really long sequences of characters, you can use Regular Expressions to match certain character classes:

Pattern	Meaning
\w	any word character (basically, any letter)
\d	any decimal character (basically, any number (though not .))
\s	any whitespace characters (tabs, spaces, newlines)
\p{NAME}	any named group (these are useful, but advanced)

Each of these character classes also has an opposite.

Pattern	Meaning
\W	any NON-word character (basically, not letters or digits but a lot of punctutation and whitespace)
\D	any NON-decimal character (basically, any non-digit)
\S	any NON-whitespace characters (most characters)
\P{NAME}	NOT a named group

Groups

Pattern	Meaning
(Pattern)	unnamed group
(?<GroupName>Pattern)	named group
(?:Pattern)	non-capturing group (this will match but you can't get it later)
(?>Pattern)	atomic group (there can be only one)

Lookaround

Pattern	Meaning
(?=Pattern)	lookahead
(?!Pattern)	negative lookahead
(?<=Pattern)	lookbehind
(?<!Pattern)	negative lookbehind