CFLib.org – Common Function Library Project

Description:
Function that formats a numeric list so that successive numbers are shown as a series. List must be numeric. For this function to be useful, list elements should be sorted in ascending order. Updated 1/14/10 by Todd Sharp (todd@cfsilence.com) to sort the list before grouping.

Return Values:
Returns a string.

Example:

<cfoutput>
#formatListAsSeries("2,1,6,4,7,8,10")#
<!--- outputs: 1-2, 4, 6-8, 10 --->
</cfoutput>

Parameters:

Full UDF Source:

/**
 * Function that formats a numeric list so that successive numbers are shown as a series.
 * 
 * @param theList      The list to parse. (Required)
 * @return Returns a string. 
 * @author Mosh Teitelbaum (mosh.teitelbaum@evoch.com) 
 * @version 2, January 14, 2010 
 */
function formatListAsSeries(theList) {
    var lastEle = "";
    var isSet = false;
    var fList = "";
    var currEle = "";
    var idx = 0;
    
    theList = listSort(theList, "numeric", "asc");
    
    for ( idx = 1; idx LTE ListLen(theList); idx = idx + 1 ) {
        currEle = ListGetAt(theList, idx);
        
        if ( Len(lastEle) EQ 0 ) {
            fList = fList & currEle;
            lastEle = currEle;
            isSet = false;
        } else if ( lastEle EQ currEle ) {
            //do nothing
        } else if ( lastEle + 1 NEQ currEle ) {
            if ( isSet ) {
                fList = fList & lastEle;
            }
            fList = fList & ", " & currEle;
            lastEle = currEle;
            isSet = false;
        } else {
        if ( NOT isSet ) {
            fList = fList & "-";
        }
        lastEle = currEle;
        isSet = true;
        }
    }

    if ( isSet ) {
        fList = fList & lastEle;
    }

    return fList;
}