CFLib.org – Common Function Library Project

Description:
Pass a list to this function to evaluate if it contains duplicates.

Return Values:
Returns a boolean.

Example:

<cfset mylist="a,b,c,d,e,b">
<cfoutput>#ListHasDupes(mylist)#</cfoutput>

Parameters:

Full UDF Source:

/**
 * Returns true if list has duplicate elements.
 * 
 * @param list      The list to check. (Required)
 * @param delim      List delimer. Defaults to a comma. (Optional)
 * @param caseCheck      Determines if checking should be case-sensitive. Defaults to false. (Optional)
 * @return Returns a boolean. 
 * @author Mike Gillespie (mike@striking.com) 
 * @version 1, May 11, 2004 
 */
function listHasDupes(list) {
    var arr=arraynew(1);
    var caseCheck=false;
    var delim=",";
    var i = 1;
    
    if (arrayLen(arguments) gt 1) delim = arguments[2];    
    if (arrayLen(arguments) gt 2) CaseCheck=Arguments[3];
    
    if(not caseCheck) list = lcase(list);
    
    arr=listToArray(list,delim);
    
    for (;i lte arraylen(arr);i=i+1 ) {
        if (listValueCount(list,arr[i],delim) gt 1) return true;
    }
    return false;
}