
Contents > Developing ColdFusion MX Applications > Using Regular Expressions in Functions > About regular expressions > Basic regular expression syntax

Basic regular expression syntax

The simplest regular expression contains only a literal characters. The literal characters must match exactly the text being searched. For example, you can use the regular expression function REFind to find the string pattern " BIG ", just as you can with the Find function:

<cfset IndexOfOccurrence=REFind(" BIG ", "Some BIG string")>
<!--- The value of IndexOfOccurrence is 5 --->

In this example, REFind must match the exact string pattern " BIG ".

To use the full power of regular expressions, combine literal characters with character sets and special characters, as in the following example:

<cfset IndexOfOccurrence=REFind(" [A-Z]+ ", "Some BIG string")>
<!--- The value of IndexOfOccurrence is 5 --->

The literal characters of the regular expression consists of the space characters at the beginning and end of the regular expression. The character set consists of that part of the regular expression in square brackets. This character set specifies to find a single uppercase letter from A to Z, inclusive. The plus sign (+) after the square brackets is a special character specifying to find one or more occurrences of the character set.

If you removed the + from the regular expression in the previous example, " [A-Z] " matches a literal space, followed by any single uppercase letter, followed by a single space. This regular expression matches " B " but not " BIG ". The REFind function returns 0 for the regular expression, meaning that it did not find a match.

You can construct very complicated regular expressions containing literal characters, character sets, and special characters. Like any programming language, the more you work with regular expressions, the more you can accomplish with them. The examples in this section are fairly basic. For more examples, see Regular expression examples.


Contents > Developing ColdFusion MX Applications > Using Regular Expressions in Functions > About regular expressions > Basic regular expression syntax

Version 6.1

Comments are no longer accepted for ColdFusion MX 6.1. ColdFusion 8 is the current version.

Send me an e-mail when comments are added to this page | Comment Report

Current page: http://livedocs.adobe.com/coldfusion/6.1/htmldocs/regexp4.htm