PHP Regular Expression Functions. PHP has many useful functions to work with regular expressions. Here is a quick cheat sheet of the main PHP regex functions. Remember that all of them are case sensitive. For more information about the native functions for PHP regular expressions, have a look at the manual. Regular Expressions / Regex Cheat Sheet Special Characters in Regular Expressions & their meanings. Character Meaning Example. Match zero, one or more of the previous.

The tables below are a reference to basic regex. While reading the rest of the site, when in doubt, you can always come back and look here. (It you want a bookmark, here's a direct link to the regex reference tables). I encourage you to print the tables so you have a cheat sheet on your desk for quick reference.
The tables are not exhaustive, for two reasons. First, every regex flavor is different, and I didn't want to crowd the page with overly exotic syntax. For a full reference to the particular regex flavors you'll be using, it's always best to go straight to the source. In fact, for some regex engines (such as Perl, PCRE, Java and .NET) you may want to check once a year, as their creators often introduce new features.
The other reason the tables are not exhaustive is that I wanted them to serve as a quick introduction to regex. If you are a complete beginner, you should get a firm grasp of basic regex syntax just by reading the examples in the tables. I tried to introduce features in a logical order and to keep out oddities that I've never seen in actual use, such as the 'bell character'. With these tables as a jumping board, you will be able to advance to mastery by exploring the other pages on the site.

How to use the tables

The tables are meant to serve as an accelerated regex course, and they are meant to be read slowly, one line at a time. On each line, in the leftmost column, you will find a new element of regex syntax. The next column, 'Legend', explains what the element means (or encodes) in the regex syntax. The next two columns work hand in hand: the 'Example' column gives a valid regular expression that uses the element, and the 'Sample Match' column presents a text string that could be matched by the regular expression.
You can read the tables online, of course, but if you suffer from even the mildest case of online-ADD (attention deficit disorder), like most of us… Well then, I highly recommend you print them out. You'll be able to study them slowly, and to use them as a cheat sheet later, when you are reading the rest of the site or experimenting with your own regular expressions.
Enjoy!
If you overdose, make sure not to miss the next page, which comes back down to Earth and talks about some really cool stuff: The 1001 ways to use Regex.

Regex Accelerated Course and Cheat Sheet

For easy navigation, here are some jumping points to various sections of the page:
✽ Characters
✽ Quantifiers
✽ More Characters
✽ Logic
✽ More White-Space
✽ More Quantifiers
✽ Character Classes
✽ Anchors and Boundaries
✽ POSIX Classes
✽ Inline Modifiers
✽ Lookarounds
✽ Character Class Operations
✽ Other Syntax
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Characters

Character	Legend	Example	Sample Match
d	Most engines: one digit from 0 to 9	file_dd	file_25
d	.NET, Python 3: one Unicode digit in any script	file_dd	file_9੩
w	Most engines: 'word character': ASCII letter, digit or underscore	w-www	A-b_1
w	.Python 3: 'word character': Unicode letter, ideogram, digit, or underscore	w-www	字-ま_۳
w	.NET: 'word character': Unicode letter, ideogram, digit, or connector	w-www	字-ま‿۳
s	Most engines: 'whitespace character': space, tab, newline, carriage return, vertical tab	asbsc	a b c
s	.NET, Python 3, JavaScript: 'whitespace character': any Unicode separator	asbsc	a b c
D	One character that is not a digit as defined by your engine's d	DDD	ABC
W	One character that is not a word character as defined by your engine's w	WWWWW	*-+=)
S	One character that is not a whitespace character as defined by your engine's s	SSSS	Yoyo

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Quantifiers

Quantifier	Legend	Example	Sample Match
+	One or more	Version w-w+	Version A-b1_1
{3}	Exactly three times	D{3}	ABC
{2,4}	Two to four times	d{2,4}	156
{3,}	Three or more times	w{3,}	regex_tutorial
*	Zero or more times	A*B*C*	AAACC
?	Once or none	plurals?	plural

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More Characters

Character	Legend	Example	Sample Match
.	Any character except line break	a.c	abc
.	Any character except line break	.*	whatever, man.
.	A period (special character: needs to be escaped by a )	a.c	a.c
	Escapes a special character	.*+? $^/	.*+? $^/
	Escapes a special character	[{()}]	[{()}]

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Logic

Logic	Legend	Example	Sample Match
|	Alternation / OR operand	22|33	33
( … )	Capturing group	A(nt|pple)	Apple (captures 'pple')
1	Contents of Group 1	r(w)g1x	regex
2	Contents of Group 2	(dd)+(dd)=2+1	12+65=65+12
(?: … )	Non-capturing group	A(?:nt|pple)	Apple

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More White-Space

Character	Legend	Example	Sample Match
t	Tab	Ttw{2}	T ab
r	Carriage return character	see below
n	Line feed character	see below
rn	Line separator on Windows	ABrnCD	AB CD
N	Perl, PCRE (C, PHP, R…): one character that is not a line break	N+	ABC
h	Perl, PCRE (C, PHP, R…), Java: one horizontal whitespace character: tab or Unicode space separator
H	One character that is not a horizontal whitespace
v	.NET, JavaScript, Python, Ruby: vertical tab
v	Perl, PCRE (C, PHP, R…), Java: one vertical whitespace character: line feed, carriage return, vertical tab, form feed, paragraph or line separator
V	Perl, PCRE (C, PHP, R…), Java: any character that is not a vertical whitespace
R	Perl, PCRE (C, PHP, R…), Java: one line break (carriage return + line feed pair, and all the characters matched by v)

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More Quantifiers

Quantifier	Legend	Example	Sample Match
+	The + (one or more) is 'greedy'	d+	12345
?	Makes quantifiers 'lazy'	d+?	1 in 12345
*	The * (zero or more) is 'greedy'	A*	AAA
?	Makes quantifiers 'lazy'	A*?	empty in AAA
{2,4}	Two to four times, 'greedy'	w{2,4}	abcd
?	Makes quantifiers 'lazy'	w{2,4}?	ab in abcd

Regular Expression C# Cheat Sheet

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Character Classes

Character	Legend	Example	Sample Match
[ … ]	One of the characters in the brackets	[AEIOU]	One uppercase vowel
[ … ]	One of the characters in the brackets	T[ao]p	Tap or Top
-	Range indicator	[a-z]	One lowercase letter
[x-y]	One of the characters in the range from x to y	[A-Z]+	GREAT
[ … ]	One of the characters in the brackets	[AB1-5w-z]	One of either: A,B,1,2,3,4,5,w,x,y,z
[x-y]	One of the characters in the range from x to y	[ -~]+	Characters in the printable section of the ASCII table.
[^x]	One character that is not x	[^a-z]{3}	A1!
[^x-y]	One of the characters not in the range from x to y	[^ -~]+	Characters that are not in the printable section of the ASCII table.
[dD]	One character that is a digit or a non-digit	[dD]+	Any characters, inc- luding new lines, which the regular dot doesn't match
[x41]	Matches the character at hexadecimal position 41 in the ASCII table, i.e. A	[x41-x45]{3}	ABE

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Anchors and Boundaries

Anchor	Legend	Example	Sample Match
^	Start of string or start of line depending on multiline mode. (But when [^inside brackets], it means 'not')	^abc .*	abc (line start)
$	End of string or end of line depending on multiline mode. Many engine-dependent subtleties.	.*? the end$	this is the end
A	Beginning of string (all major engines except JS)	Aabc[dD]*	abc (string.. ..start)
z	Very end of the string Not available in Python and JS	the endz	this is..n..the end
Z	End of string or (except Python) before final line break Not available in JS	the endZ	this is..n..the endn
G	Beginning of String or End of Previous Match .NET, Java, PCRE (C, PHP, R…), Perl, Ruby
b	Word boundary Most engines: position where one side only is an ASCII letter, digit or underscore	Bob.*bcatb	Bob ate the cat
b	Word boundary .NET, Java, Python 3, Ruby: position where one side only is a Unicode letter, digit or underscore	Bob.*bкошкаb	Bob ate the кошка
B	Not a word boundary	c.*BcatB.*	copycats

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POSIX Classes

Character	Legend	Example	Sample Match
[:alpha:]	PCRE (C, PHP, R…): ASCII letters A-Z and a-z	[8[:alpha:]]+	WellDone88
[:alpha:]	Ruby 2: Unicode letter or ideogram	[[:alpha:]d]+	кошка99
[:alnum:]	PCRE (C, PHP, R…): ASCII digits and letters A-Z and a-z	[[:alnum:]]{10}	ABCDE12345
[:alnum:]	Ruby 2: Unicode digit, letter or ideogram	[[:alnum:]]{10}	кошка90210
[:punct:]	PCRE (C, PHP, R…): ASCII punctuation mark	[[:punct:]]+	?!.,:;
[:punct:]	Ruby: Unicode punctuation mark	[[:punct:]]+	‽,:〽⁆

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Inline Modifiers

None of these are supported in JavaScript. In Ruby, beware of (?s) and (?m).

Modifier	Legend	Example	Sample Match
(?i)	Case-insensitive mode (except JavaScript)	(?i)Monday	monDAY
(?s)	DOTALL mode (except JS and Ruby). The dot (.) matches new line characters (rn). Also known as 'single-line mode' because the dot treats the entire input as a single line	(?s)From A.*to Z	From A to Z
(?m)	Multiline mode (except Ruby and JS) ^ and $ match at the beginning and end of every line	(?m)1rn^2$rn^3$	1 2 3
(?m)	In Ruby: the same as (?s) in other engines, i.e. DOTALL mode, i.e. dot matches line breaks	(?m)From A.*to Z	From A to Z
(?x)	Free-Spacing Mode mode (except JavaScript). Also known as comment mode or whitespace mode	(?x) # this is a # comment abc # write on multiple # lines [ ]d # spaces must be # in brackets	abc d
(?n)	.NET, PCRE 10.30+: named capture only	Turns all (parentheses) into non-capture groups. To capture, use named groups.
(?d)	Java: Unix linebreaks only	The dot and the ^ and $ anchors are only affected by n
(?^)	PCRE 10.32+: unset modifiers	Unsets ismnx modifiers

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Lookarounds

Lookaround	Legend	Example	Sample Match
(?=…)	Positive lookahead	(?=d{10})d{5}	01234 in 0123456789
(?<=…)	Positive lookbehind	(?<=d)cat	cat in 1cat
(?!…)	Negative lookahead	(?!theatre)thew+	theme
(?<!…)	Negative lookbehind	w{3}(?<!mon)ster	Munster

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Character Class Operations

Class Operation	Legend	Example	Sample Match
[…-[…]]	.NET: character class subtraction. One character that is in those on the left, but not in the subtracted class.	[a-z-[aeiou]]	Any lowercase consonant
[…-[…]]	.NET: character class subtraction.	[p{IsArabic}-[D]]	An Arabic character that is not a non-digit, i.e., an Arabic digit
[…&&[…]]	Java, Ruby 2+: character class intersection. One character that is both in those on the left and in the && class.	[S&&[D]]	An non-whitespace character that is a non-digit.
[…&&[…]]	Java, Ruby 2+: character class intersection.	[S&&[D]&&[^a-zA-Z]]	An non-whitespace character that a non-digit and not a letter.
[…&&[^…]]	Java, Ruby 2+: character class subtraction is obtained by intersecting a class with a negated class	[a-z&&[^aeiou]]	An English lowercase letter that is not a vowel.
[…&&[^…]]	Java, Ruby 2+: character class subtraction	[p{InArabic}&&[^p{L}p{N}]]	An Arabic character that is not a letter or a number

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Cheat Sheet Regular Expression C

Cheat Sheet Regular Expression

Other Syntax

Syntax	Legend	Example	Sample Match
K	Keep Out Perl, PCRE (C, PHP, R…), Python's alternate regex engine, Ruby 2+: drop everything that was matched so far from the overall match to be returned	prefixKd+	12
Q…E	Perl, PCRE (C, PHP, R…), Java: treat anything between the delimiters as a literal string. Useful to escape metacharacters.	Q(C++ ?)E	(C++ ?)

The 1001 ways to use Regex

Regular Expression Cheat Sheet Python Pdf

Need a little extra help with those Regular Expression(regex) functions? Then look no further! Here, I have put together the best top 10 regex cheat sheets for you to download, print and pin to the bathroom wall!!

This cheat sheets will be a great reference when you need to put them in your scripts when you are web scraping and trying to find information or when you need help to authenticate users and passwords!

All the regex cheat sheets in this article are 100% free. All links open a new tab (feel free to open all the links without losing this page!)

Cheat Sheet 1: Rexegg.com

This first sheet is from Rexegg.com. The entire list is one that is commonly used Regex expressions in Python and other languages. This list includes Characters, Quantifiers and more. It will even tell you what language this expression can be used in! This makes it a lot easier when you go to write a regex in your language preference. This website really does emphasize looking at the tables for the expressions by keeping the tables bright on a black background. Making it easy to read the table but very difficult to read the information on regex itself.

Pros: Tables are bright and easy to read. Contains a lot of information shorthand to write regex

Cons: Information on the page is very dark and difficult to read.

Cheat Sheet 2: Regular Expressions cheat sheet – MIT

This second sheet was written by MIT. It is very spartan with no color and straight to the point on what the expressions are and what they do. This is the perfect cheat sheet if you do not want to be distracted by color or graphics. However, since it is very dry in the manner of text, I would not suggest this particular cheat sheet to someone who is just learning regular expressions since the explanations and examples are minimal.

Pros: Clean text, no colors for distraction, contains a lot of information shorthand to write regex

Cons: Too spartan for a total beginner in Regex

Cheat Sheet 3: Cheatography.com

I really love this website! This sheet was put together by Dave Child for regular expressions. It’s a nice quick reference guide pdf you can print in bright pink. It is easy to read and rated ‘E’ for everyone! It includes symbols, ranges, grouping, assertions and more with sample patterns to help get you on your way! Cheatography is one of my favorite websites for cheat sheet because they have so many on so many different topics and in many styles. It’s nice to find a one stop shop for cheat sheets.

Pros: Explains regex easily, uses soft colors, contains a lot of information.

Cons: Color may be distracting to some.

Cheat Sheet 4: Dev.to

Dev.to is a great place for new and experienced developers! This regex list was written by Catherine on her dev.to profile where she explains regex expressions in Java-script she has compiled with her resources at the bottom of here article.

Pros: Great spot to read someone else’s experience in regex and to gather new resources

Cons: More of an article than an actual pdf to print.

Daisetz Teitaro Suzuki is an eloquent international spokesman for one of these traditions: the Japanese variant of Buddhism known as Zen. Suzuki, in full Daisetsu Teitarō Suzuki, (born October 18, 1870, Kanazawa, Japan—died July 12, 1966, Kamakura), Japanese Buddhist scholar and thinker who was the chief interpreter of Zen Buddhism to the West. Suzuki studied at the University of Tokyo. Daisetz teitaro suzuki. Daisetz Teitaro Suzuki (1870-1966) was a Japanese translator, teacher, and constructive interpreter of Zen Buddhist thought to the West. Teitaro Suzuki was born in Kanazawa in western Japan on October 18, 1870. His ancestors as well as his father, grandfather,.

Cheat Sheet 5: Last Call – The Rapid API Blog

This is another great website for developers! This cheat sheet is also very easy to read and understand. It has additional resources beneath the code written. There are no examples in the post but there is shorthand explanations for each expression, characters and quantifiers. I would not suggest this particular cheat sheet for a beginner.

Pros: Great for those who understand regex and don’t have a need for examples

Cons: Not for Beginners since it has minimal explanation

Cheat Sheet 6: GREP

Here is another one! This one is minimal in color to keep distractions down. Key words are in red and examples are done in yellow. There are minimal explanations in the color keys. This sheet is for the advanced regex user who only needs a quick reference. It is clean and easy to read. It covers all of the information needed to write your own regex!

Pros: Written cleanly, additional resources at the bottom, to the point.

Cons: Not for the regex beginner.

Cheat Sheet 7: Regex chart

This Regex sheet is a very quick one with only the characters, the meaning and an example. This one is also for the advanced regex user. There is only the bare minimum here and this particular sheet does not contain quantifiers or expressions. There is a link however to a regex character classes cheat sheet.

Pros: Very quick reference of only character in regex

Cons: Not for a beginner regex user.

Cheat Sheet 8: Keycdn

Here is another awesome website to learn Regular expressions from! It goes over what regex is, gives you the list of expressions and gives you 2 separate examples on how regex is used in find numbers and emails. Near the bottom it even give you 3 tools to help you learn how to build a proper regex formula! These test sites will help you not only to build regex but compile it and make sure it running correctly before implementing it into your code.

Pros: Not only information but tools as well!

Cons: none as far I can see.

Cheat Sheet 9: MDN Web Docs

This regex syntax cheat sheet is on one of my absolute favorite places to learn about web development!! Named Moz:a (pronounced Mozilla) this particular guide will walk through not only the syntax but take you to the complete guide on regex! This cheat sheet is rated ‘E’ for everyone! It has clear examples and explanations on beginner and advanced regex characters and expressions.

Pros: Great for Everyone!!

Cons: N/A

Cheat Sheet 10: Dataquest

The final cheat sheet!! This final cheat sheet is from Dataquest. This particular cheat sheet was written specifically for Python!! This pdf is downloadable for free and explains each character and expression in detail. There is a lot of information packed in this pdf each under the proper heading and minimal color for the least number of distractions.

Pros: A lot of information pack in with minimal color.

Cons: How big is avogadro's number. Can appear to be overwhelming at first glance to a beginner.

I would like to thank you for taking the time to read this article. I hope that you are able to use at least one of these cheat sheets the next time you need to put a regular expression in your coding! The best way to learn though is to practice!! Good luck with writing your regex!!

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