Regex Quick Reference

.	Any character except newline.
\.	A period (and so on for \*, \(, \\, etc.)
^	The start of the string.
$	The end of the string.
\d,\w,\s	A digit, word character [A-Za-z0-9_], or whitespace.
\D,\W,\S	Anything except a digit, word character, or whitespace.
[abc]	Character a, b, or c.
[a-z]	a through z.
[^abc]	Any character except a, b, or c.
aa|bb	Either aa or bb.
?	Zero or one of the preceding element.
*	Zero or more of the preceding element.
+	One or more of the preceding element.
{n}	Exactly n of the preceding element.
{n,}	n or more of the preceding element.
{m,n}	Between m and n of the preceding element.
??,*?,+?, {n}?, etc.	Same as above, but as few as possible.
(expr)	Capture expr for use with \1, etc.
(?:expr)	Non-capturing group.
(?=expr)	Followed by expr.
(?!expr)	Not followed by expr.

And for a free online regex evaluation you can refer here .