Regular Expression Examples

The following examples show some regular expressions and describe what they match:

Expression

Description

[\?&]value=
A URL parameter value in a URL.

[A-Z]:(\\[A-Z0-9_]+)+
An uppercase DOS/Windows full path that (a) is not the root of a drive, and (b) has only letters, numbers, and underscores in its text.

[A-Za-z][A-Za-z0-9_]*
A ColdFusion variable with no qualifier.

([A-Za-z][A-Za-z0-9_]*)(\.[A-Za-z][A-Za-z0-9_]*)?
A ColdFusion variable with no more than one qualifier; for example, Form.VarName, but not Form.Image.VarName.

(\+|-)?[1-9][0-9]*
An integer that does not begin with a zero and has an optional sign.

(\+|-)?[1-9][0-9]*(\.[0-9]*)?
A real number.

(\+|-)?[1-9]\.[0-9]*E(\+|-)?[0-9]+
A real number in engineering notation.

a{2,4}
Two to four occurrences of "a": aa, aaa, aaaa.

(ba){3,}
At least three "ba" pairs: bababa, babababa, and so on..

Expression	Description
[\?&]value=	A URL parameter value in a URL.
[A-Z]:(\\[A-Z0-9_]+)+	An uppercase DOS/Windows full path that (a) is not the root of a drive, and (b) has only letters, numbers, and underscores in its text.
[A-Za-z][A-Za-z0-9_]*	A ColdFusion variable with no qualifier.
([A-Za-z][A-Za-z0-9_])(\.[A-Za-z][A-Za-z0-9_])?	A ColdFusion variable with no more than one qualifier; for example, Form.VarName, but not Form.Image.VarName.
(\+\|-)?[1-9][0-9]*	An integer that does not begin with a zero and has an optional sign.
(\+\|-)?[1-9][0-9](\.[0-9])?	A real number.
(\+\|-)?[1-9]\.[0-9]*E(\+\|-)?[0-9]+	A real number in engineering notation.
a{2,4}	Two to four occurrences of "a": aa, aaa, aaaa.
(ba){3,}	At least three "ba" pairs: bababa, babababa, and so on..

Regular expressions in CFML

The following examples of CFML show some common uses of regular expression functions:

Expression

Returns

REReplace (CGI.Query_String, "CFID=[0-9]+[&]*", "")
The query string with parameter CFID and its numeric value stripped out.

REReplace("I Love Jellies", "[[:lower:]]","x","ALL"
I Lxxx Jxxxxxx

REReplaceNoCase("cabaret","[A-Z]", "G","ALL")
GGGGGGG

REReplace (Report, "\$[0-9,]*\.[0-9]*", "$***.**")", "")
The string value of the variable Report with all positive numbers in the dollar format changed to "$***.**".

REFind ("[Uu]\.?[Ss]\.?[Aa}\.?", Report )
The position in the variable Report of the first occurrence of the abbreviation USA. The letters can be in either case and the abbreviation can have a period after any letter.

REFindNoCase("a+c","ABCAACCDD")
4

REReplace("There is is coffee in the the kitchen","([A-Za-z]+) [ ]+\1","*","ALL")
There * coffee in * kitchen

REReplace(report, "<[^>]*>", "", "All")
Removes all HTML tags from a string value of the report variable.

Developing ColdFusion Applications
Using Regular Expressions in Functions

Expression	Returns
REReplace (CGI.Query_String, "CFID=[0-9]+[&]*", "")	The query string with parameter CFID and its numeric value stripped out.
REReplace("I Love Jellies", "[[:lower:]]","x","ALL"	I Lxxx Jxxxxxx
REReplaceNoCase("cabaret","[A-Z]", "G","ALL")	GGGGGGG
REReplace (Report, "\$[0-9,]\.[0-9]", "$*.")", "")	The string value of the variable Report with all positive numbers in the dollar format changed to "$*.".
REFind ("[Uu]\.?[Ss]\.?[Aa}\.?", Report )	The position in the variable Report of the first occurrence of the abbreviation USA. The letters can be in either case and the abbreviation can have a period after any letter.
REFindNoCase("a+c","ABCAACCDD")	4
REReplace("There is is coffee in the the kitchen","([A-Za-z]+) [ ]+\1","*","ALL")	There * coffee in * kitchen
REReplace(report, "<[^>]*>", "", "All")	Removes all HTML tags from a string value of the report variable.