Regular Expressions Metacharacters

Metacharacter	Description	Examples
\	Escape reserved metacharacters	\$ or \. outside []
.	Any character except new line	ton. = tone
\d	Digit (0-9)	\d\d\d = 327
\D	NOT a Digit (0-9)	\D = a
\w	Word Char (Alphanumeric)	\w\w = hi
\W	NOT a Word Char (Symbols)	\W = %
\s	Whitespace (tab, space, newline)	\s = ' '
\S	NOT Whitespace	\S = a
\b	Word Boundary	\bHo in Ho HoHo, \bHo\b in Ho HoHo
\B	NOT a Word Boundary	\BHo in Ho HoHo
^	Begining of a String or Line	^Ho in Ho HoHo
$	End of a String or Line	Ho$ in Ho HoHo
[]	Matche Characters in bracket	[a-z] match a character a to z, [0-9] match a digit
[^ ]	NOT Match Characters in bracket	[^b]at will NOT match bat, [^a-z] match everything except lowercase a to z
|	Alternation (Either Or)	pand(ora|123) = pandora OR pand123
()	Group	Swi(ft) will search Swift but will ignore Swiftly
*	Match 0 or more	[a-z]* will match 0 or more characters between a to z
+	Match 1 or more	[a-z]+ will match 1 or more characters between a to z
?	Match 0 or 1 character	colo?r matches colour and color
{2}	Exact number of characters to be matched	[a-z]{2} so this matches only 2 characters between a to z
{2,10}	Range of numbers {minimum, maximum}	[a-z]{2,5} so matches characters a to z between 2 to 5 char length