regex-cheatsheet.md

REGEX cheatsheet

From regexone.com and regexr.com.

Contents

• Characters Classes
• Positions
• Quantifiers
• Escaped Characters
• Capture Groups

Character Classes

Expression	Pattern
abc...	Letters
123...	Digits
[abc]	Any character in the set
[^abc]	Any character not in the set
[a-z]	Characters having a code between the two specified characters (inclusive)
.	Any character
\w	Any alphanumeric (A-Z, a-z, 0-9) character
\W	Any non-alphanumeric character
\d	Any digit
\D	Any non-digit characters
\s	Any whitespace (spaces, tabs, line breaks)
\S	Any non-whitespace character

Positions

Expression	Pattern
^	Start of the string
$	End of the string
\b	Boundary between a word character and non-word character
\B	Any position that is not a word boundary

Quantifiers

Expression	Pattern
*	Zero or more repetitions
+	One or more repetitions
?	Optional character
{m}	m repetitions
{m,}	m or more repetitions
{m, n}	m to n repetitions
(abc|def)	abc or def

Escaped Characters

Expression	Pattern
\+	Character with special meaning
\xFF	Character in hexadecimal form
\t	Tab character
\n	Line feed character
\r	Carriage return character
\0	Null character

Capture Groups

Expression	Pattern
(abc)	Capture group
\1	Result of a capture group