CFLib.org – Common Function Library Project

Description:
Counts the unique items in a list. Useful when you don't need to de-dupe a list.

Return Values:
Returns a number.

Example:

<cfset myList="1,1,1,2,3,4,4,4,5">
<cfoutput>#listCountUnique(myList)# unique item(s) in a list of #listLen(myList)# item(s).</cfoutput>

Parameters:

Full UDF Source:

/**
 * Count unique items in a list. (Case-sensitive)
 * 
 * @param lst      List to parse. (Required)
 * @return Returns a number. 
 * @author Al Everett (everett.al@gmail.com) 
 * @version 1, November 14, 2007 
 */
function listCountUnique(lst) {
  var i         = 0;
  var delim     = ",";
  var countList = "";
  var lstArray  = "";

  if (arrayLen(arguments) gt 1) delim = arguments[2];
    
  lstArray = listToArray(lst,delim);
    
  for (i = 1; i LTE arrayLen(lstArray); i = i + 1) {
    if (listFind(countList,lstArray[i],delim) eq 0) {
      countList=listAppend(countList,lstArray[i]);
    }
  }

  return listLen(countList);
}