Regex - Cheatsheet

Character classes

.               any character except newline
\w \d \s        word, digit, whitespace
\W \D \S        not word, digit, whitespace
[abc]           any of a, b, or c
[^abc]          not a, b, or c
[a-g]           character between a & g


^abc$           start / end of the string
\b \B           word, not-word boundary

Escaped characters

\. \* \\        escaped special characters
\t \n \r        tab, linefeed, carriage return

Groups & Lookaround

(abc)           capture group
\1              backreference to group #1
(?:abc)         non-capturing group
(?=abc)         positive lookahead
(?!abc)         negative lookahead

Quantifiers & Alternation

a* a+ a?        0 or more, 1 or more, 0 or 1
a{5} a{2,}      exactly five, two or more
a{1,3}          between one & three
a+? a{2,}?      match as few as possible
ab|cd           match ab or cd