.Any character
^Start of string
$End of string
*0 or more
+1 or more
?0 or 1
{n}Exactly n
{n,m}Between n and m
\dDigit [0-9]
\wWord [a-zA-Z0-9_]
\sWhitespace
\bWord boundary
[abc]Character class
[^abc]Negated class
(abc)Capture group
(?:abc)Non-capture group
a|bAlternation
(?=abc)Positive lookahead
(?!abc)Negative lookahead
(?<=a)Positive lookbehind