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Regex Memo - Regular Expression Cheat Sheet

Quick reference cheat sheet for Regular Expression syntax.

Special Characters

.Any character (except newline)

\dDigit [0-9]

\DNon-digit

\wWord character [a-zA-Z0-9_]

\WNon-word character

\sWhitespace

\SNon-whitespace

\bWord boundary

Quantifiers

*0 or more times

+1 or more times

?0 or 1 time

{n}Exactly n times

{n,}At least n times

{n,m}Between n and m times

*?0+ times (lazy)

+?1+ times (lazy)

Anchors & Groups

^Start of string

$End of string

(abc)Capture group

(?:abc)Non-capturing group

(?=abc)Positive lookahead

(?!abc)Negative lookahead

(?<=abc)Positive lookbehind

(?<!abc)Negative lookbehind

Character Classes

[abc]a, b, or c

[^abc]Not a, b, or c

[a-z]From a to z

[A-Z]From A to Z

[0-9]From 0 to 9

a|ba or b

Flags

gGlobal — find all matches

iCase-insensitive

mMultiline

sDotall (. matches newline)

uUnicode

Common Patterns

^[\w.-]+@[\w.-]+\.\w{2,}$Email

^https?://[\w.-]+(?:/[\w.-]*)*$URL

^\d{1,3}(\.\d{1,3}){3}$IPv4

^#?([0-9a-fA-F]{3}|[0-9a-fA-F]{6})$Hex Color

^\d{4}-\d{2}-\d{2}$Date (YYYY-MM-DD)

Regex Memo - Regular Expression Cheat Sheet

Special Characters

Quantifiers

Anchors & Groups

Character Classes

Flags

Common Patterns

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