User Guide

580 Chapter 3: ColdFusion Functions
ListPrepend
Description
Inserts an element at the beginning of a list.
Returns
A copy of the list, with value inserted at the first position.
Category
List functions
Function syntax
ListPrepend(list, value [, delimiters ])
See also
ListAppend, ListInsertAt, ListSetAt
Parameters
Usage
When prepending an element to a list, ColdFusion inserts a delimiter. If delimiters contains more
than one delimiter character, ColdFusion uses the first delimiter in the string; if
delimiters is
omitted, ColdFusion uses a comma.
ColdFusion ignores empty list elements; thus, the list "a,b,c,,,d" has four elements.
If the
delimiters parameter is the empty string (""), ColdFusion returns the contents of the
value parameter.
To add an element to the beginning or end of a list, Macromedia recommends that you do so
with code such as the following, rather than with the
ListAppend or ListPrepend functions:
<cfset MyValue = "another element">
<cfif listLen(myList) is 0>
<cfset myList = MyValue>
<cfelse>
<cfset myList = myList & ", " & MyValue>
</cfif>
Example
<!--- This example shows ListPrepend --->
<cfquery name = "GetParkInfo" datasource = "cfsnippets">
SELECT PARKNAME,CITY,STATE
FROM PARKS
WHERE PARKNAME LIKE ‘DE%’
</cfquery>
<cfset temp = ValueList(GetParkInfo.ParkName)>
Parameter Description
list A list or a variable that contains one.
value An element or a list of elements.
delimiters A string or a variable that contains one. Character(s) that separate list elements.
Default: comma.
If this parameter contains more than one character, ColdFusion only uses the first
character and ignores the others.