Viewing regular expressions operators

Expressions in simple data patterns can be build using different operators.

Range Operator

Expression	Description
[ ]	Can contain a range of characters which can be separated by a "-" char for inclusive matching of all chars between two endpoints
[0-9]	Will match any digit
[a-z]	Will match an alphabetic char
[a-z0-9]	Will match an alphanumeric char
^	The "Negate/Not" operator can be used to match against anything except what is defined in the range operator. For example, [^0-9] will match anything but a digit char.

Character Classes

Expression	Description
.	Will match any char
\b	Will match word boundaries at the beginning or end of a sequence of alphanumeric characters
\B	Will match non-word boundaries (opposite of \b)
\d	Will match a digit char (shorthand for [0-9])
\D	Will match non-digit char (shorthand for [^0-9])
\s	Will match any whitespace char including spaces, tabs, line feeds, newlines, etc
\S	Will match a non-whitespace char
\w	Will match any "word" char (shorthand for or [a-zA-Z0-9_])
\W	Will match a non-word char
\xHH	Will match a hexadecimal character represented by the hex code

Occurrence Operators

Expression	Description
*	Will match zero or more occurrences of the previous char or expression
+	Will match one or more occurrences of the previous char or expression
?	Will match zero or one occurrence of the previous char or expression
{N}	Will match exactly N occurrences or the previous char or expression
{N,M}	Will match from N up to M occurrences or the previous char or expression
{N,}	Will match at least N occurrences of the previous char or expression

Grouping Operator

Expression	Description
( )	Can contain a set of characters which must all be present for the match to occur. Parenthesis can contain character classes,
|	The "Or" operator can be used to match against different sets of characters enclosed in parenthesis. For example, (dog|cat) will match if dog or cat is present.
Flags
(?Lsu)	Flag operator used at the beginning of the grouping operator. Set 'L', 's', 'u' to set the following flags: L - locale dependent, s - dot matches all, u - unicode