MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX, Develop Manual

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Types of regular expression technologies 159
Regular expressions in CFML
The following examples of CFML show some common uses of regular expression functions:
Types of regular expression technologies
Many types of regular expression technologies are available to programmers. JavaScript, Perl, and
POSIX are all examples of different regular expression technologies. Each technology has its own
syntax specifications and is not necessarily compatible with other technologies.
ColdFusion supports regular expressions that are Perl compliant with a few exceptions:
•
A period, ., always matches newlines.
•
In replacement strings, use \n instead of $n for backreference variables. ColdFusion escapes all
$ in the replacement string.
•
You do not have to escape backslashes in replacement strings. ColdFusion escapes them, with
the exception of case conversion sequences or escaped versions (e.g. \u or \\u).
•
Embedded modifiers ( (?i), etc. ) always affect the entire expression, even if they are inside a
group.
•
\Q and the combinations \u\L and \l\U are not supported in replacement strings.
(\+|-)?[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 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.
Expression Description