ColdFusion 9.0 Resources

ListSetAt

Description

Replaces the contents of a list element.

Returns

A copy of a list, with a new value assigned to the element at a specified position.

Function syntax

ListSetAt(list, position, value [, delimiters, includeEmptyValues ])

History

ColdFusion MX: Changed delimiter modification: ColdFusion MX does not modify delimiters in the list. (In earlier releases, in some cases, replaced delimiters with the first character in the delimiters parameter.)

Parameters

Parameter	Description
`includeEmptyValues`	Optional. Set to `yes` to include empty values.
`list`	A list or a variable that contains one.
`position`	A positive integer or a variable that contains one. Position at which to set a value. The first list position is 1.
`value`	An element or a list of elements.
`delimiters`	A string or a variable that contains one. Characters that separate list elements. The default value is comma. If this parameter contains more than one character, ColdFusion processes each occurrence of each character as a delimiter.

Usage

When assigning an element to a list, ColdFusion inserts a delimiter. If delimiters contains more than one delimiter, ColdFusion uses the first delimiter in the string, or, if delimiters was omitted, a comma.

ColdFusion ignores empty list elements; thus, the list "a,b,c,,,d" has four elements.

Example

<h3>ListSetAt Example</h3> 
<!--- Find a list of users who wrote messages ---> 
<cfquery name = "GetMessageUser" datasource = "cfdocexamples"> 
SELECT Username, Subject, Posted 
FROMMessages 
</cfquery> 
 
<cfset temp = ValueList(GetMessageUser.Subject)> 
 
<!--- loop through the list and show it with ListGetAt ---> 
<h3>This is a list of <cfoutput>#ListLen(temp)#</cfoutput> 
subjects posted in messages.</h3> 
 
<cfset ChangedElement = ListGetAt(temp, 2)> 
<cfset TempToo = ListSetAt(temp, 2, "I changed this subject", ",")> 
<ul> 
<cfloop From = "1" To = "#ListLen(temptoo)#" INDEX = "Counter"> 
    <cfoutput><li>(#Counter#) SUBJECT: #ListGetAt(temptoo, Counter)# 
    </cfoutput> 
</cfloop> 
</ul> 
<p>Note that element 2, "<cfoutput>#changedElement#</cfoutput>",  
    has been altered to "I changed this subject" using ListSetAt.