Regular Expression Cheat Sheets and Resources

Quick Regex Reference

Character	Meaning	Example
*	Match zero, one or more of the previous	`Ah*` matches "`Ahhhhh`" or "`A`"
?	Match zero or one of the previous	`Ah?` matches "`Al`" or "`Ah`"
+	Match one or more of the previous	`Ah+` matches "`Ah`" or "`Ahhh`" but not "`A`"
\	Used to escape a special character	`Hungry\?` matches "`Hungry?`"
.	Wildcard character, matches any character	`do.*` matches "`dog`", "`door`", "`dot`", etc.
( )	Group characters	See example for `\|`
[ ]	Matches a range of characters	`[cbf]ar` matches "car", "bar", or "far" `[0-9]+` matches any positive integer `[a-zA-Z]` matches ascii letters a-z (uppercase and lower case) `[^0-9]` matches any character not 0-9.
\|	Matche previous OR next character/group	`(Mon\|Tues)day` matches "Monday" or "Tuesday"
{ }	Matches a specified number of occurrences of the previous	`[0-9]{3}` matches "315" but not "31" `[0-9]{2,4}` matches "12", "123", and "1234" `[0-9]{2,}` matches "1234567..."
^	Beginning of a string. Or within a character range `[]` negation.	`^http` matches strings that begin with http, such as a url. `[^0-9]` matches any character not 0-9.
$	End of a string.	`ing$` matches "exciting" but not "ingenious"