Quick Reference
.Any character (except newline)
\dDigit (0-9)
\DNon-digit
\wWord character (a-z, A-Z, 0-9, _)
\WNon-word character
\sWhitespace
\SNon-whitespace
\bWord boundary
^Start of string/line
$End of string/line
*0 or more
+1 or more
?0 or 1 (optional)
{n}Exactly n times
{n,m}Between n and m times
[abc]Character class (a, b, or c)
[^abc]Negated class (not a, b, c)
(abc)Capture group
(?:abc)Non-capture group
(?=abc)Positive lookahead
(?!abc)Negative lookahead
(?<=abc)Positive lookbehind
a|bAlternation (a or b)
\1Backreference to group 1
$1Group 1 in replacement