onGroups and Ranges

Quantifiers

Anchors

.

^

Start of string

*

0 or more

\A

Start of string

+

1 or more

$

End of string

?

0 or 1

(a|b)

a or b

\Z

End of string

{3}

Exactly 3

(...)

Group

\b

Word boundary

{3,}

3 or more

(?:...)

Passive Group

\B

Not word boundary

{3,5}

3, 4 or 5

[abc]

Range (a or b or c)

\<

Start of word

[^abc]

Not a or b or c

\>

End of word

[a-q]

Letter between a and q

[A-Q]

Upper case letter

Character Classes
\c

White space

\S

Not white space

\d

Digit

\D

Word

\W

Not word

\x

Hexadecimal digit

\O

Octal digit

Ungreedy version of "x"

Not digit

\w

between A and Q

"x" below represents a quantifier

Control character

\s

new line (\n)

Quantifier Modifiers

x?

Escape Character
\

Any character except

Escape Character

[0-7]

Digit between 0 and 7

\n

nth group/subpattern
Note: Ranges are inclusive.
Pattern Modifiers g Case-insensitive

m

Metacharacters (must be escaped)

Global match

i

Multiple lines

^

[:lower:]

All letters

[:alnum:]

Digits and letters

[:digit:]

Digits

*

x

Allow comments and

\

+

|

?

<

>

white space in pattern e Evaluate replacement

U

Ungreedy pattern

Lower case letters

[:alpha:]

Treat string as single line

{

)
Upper case letters

s

(

[:upper:]

.

$

POSIX

[

[:xdigit:]
[:punct:]

Hexadecimal digits
Punctuation

[:blank:]

Space and