Description
Determines the number of elements in a list. Integer; the number of elements in a list.
ListLen(list [, delimiters ]) ListLen(list [, delimiters, includeEmptyValues ])
See also
ListAppend, ListDeleteAt, ListInsertAt, ListPrepend; Lists in Data types- Developing guide in the Developing ColdFusion Applications
Parameters
Parameter |
Description |
|---|---|
list |
A list or a variable that contains one. |
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. |
includeEmptyValues |
If includeEmptyValues is set to true, all empty values in the list will be considered when computing length. If set to false, the empty list elements are ignored. |
Usage
ColdFusion ignores empty list elements; thus, the list "a,b,c,,,d" has four elements.Here are some examples of ListLen processing:
Statement |
Output |
Comment |
|---|---|---|
ListLen('a,b, c,,,d') |
4 |
Third element is " c" |
ListLen('a,b, c,,,d',',') |
4 |
Fourth element is "d'" |
ListLen('elem_1__elem_2__elem_3') |
1 |
|
ListLen('elem*1**elem*2**elem*3') |
1 |
|
ListLen('elem_1__elem_2_elem_3','') |
6 |
|
| ListLen("1,,3", ",", true) | 3 |
Example
<h3>ListLen 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.Username)> <!--- loop through the list and show it with ListGetAt ---> <h3>This is a list of usernames who have posted messages <cfoutput>#ListLen(temp)#</cfoutput> users.</h3> <ul> <cfloop From = "1" TO = "#ListLen(temp)#" INDEX = "Counter"> <cfoutput><li>Username #Counter#: #ListGetAt(temp, Counter)#</cfoutput> </cfloop> </ul>
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