Skip to content

Instantly share code, notes, and snippets.

@lyndametref

lyndametref/RegexCheatsheet.md

Last active September 5, 2016 08:28
Show Gist options
  • Save lyndametref/9e729e1f52cef218da9c9d6ce4bce7bb to your computer and use it in GitHub Desktop.
Save lyndametref/9e729e1f52cef218da9c9d6ce4bce7bb to your computer and use it in GitHub Desktop.
Download ZIP
Regex Cheatsheet
Raw
RegexCheatsheet.md

Anchors

^	Start of line or start of string
$	End of line or end of string
\A \Z Start/end of string
\b Word boundary
\B Not word boundary
\< \> Start/End of word

Characters types

.	Matches any character except new line (\n)
\n New line
\r Carriage return
\t Tab
\s Whitespace
\S Non-whitespace character
\c Control character
\d Digit
\D Not digit
\w Word
\W Not word

Assertions

?= Lookahead assertion
?! Negative lookahead
?<= Lookbehind assertion
?!= or ?<! Negative lookbehind
?() Condition [if then]
?()| Condition [if then else]

Quantifiers

* Repeat 0 or more times
+ Repeat 1 or more times
{3} Repeat exactly 3 times
{3,} 3 or more times
? Repeat 0 or 1 time
{3,5} Repeat 3, 4 or 5
Add a ? to a quantifier to make it ungreedy.

Meta characters to escape with \

^ [ ] . $ { } * ( ) \ +  | ? < >

Replacement

(...) Group (for string extraction)
(?:...) Passive (non-c­apt­uring) group
$1 "­xyz­" in /^(?:a­bc)­(xyz)$/
$2 "­xyz­" in /^(abc­(xy­z))$/

Ranges

(a|b) a or b
[abc] Range (a or b or c)
[^abc] Not (a or b or c)
[a-q] Lower case letter from a to q
[A-Q] Upper case letter from A to Q
[0-7] Digit from 0 to 7
[a-z0-9]	The set of characters can include a range

Inspired from

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment