# CFLib.org – Common Function Library Project

## listVenn(listA, listB, returnListType[, listADelimiter][, listBDelimiter][, returnListDelimiter])

##### Last updated February 14, 2006

Version: 1 | Requires: CF5 | Library: StrLib

Description:
ListVenn requires two lists and a return list type. The possible return list types are: AandB (intersection) AorB (union) AnotB (unique to list A) BnotA (unique to list B) This one UDF accomplishes the tasks currently served by ListCompare, ListInCommon, and ListUnion (with the exception of the sorting option that ListUnion offers).

Return Values:
Returns a list.

Example:

<CFSet ListA = "a|b|c|d|e|f|g|h">
<CFSet ListB = "a,v,e,g,h,j,q,r,c,m,t,y">
<CFSet ListC = "">

<CFSet AandB    = listVenn(ListA,ListB,"AandB","|",",","~")>
<CFSet AorB        = listVenn(ListA,ListB,"AorB","|",",")>
<CFSet AnotB    = listVenn(ListA,ListB,"AnotB","|",",","+")>
<CFSet BnotA    = listVenn(ListA,ListB,"BnotA","|",",","-")>

<CFOutput>
Original lists:<br>
ListA : #ListA#<br>
ListB : #ListB#<br>

NewLists:<br>
AandB : #AandB#<br>
AorB  : #AorB#<br>
AnotB : #AnotB#<br>
BnotA : #BnotA#<br>
</CFOutput>

Parameters:

Name Description Required
listA The first list. Yes
listB The second list. Yes
returnListType Return list type. Values can be: AandB, AorB, AnotB, BnotA Yes
listADelimiter List A delimiter. Defaults to a comma. No
listBDelimiter List B delimiter. Defaults to a comma. No
returnListDelimiter Return list delimiter. Defaults to a comma. No

Full UDF Source:

/**
* Performs venn type operations on two lists.
*
* @param listA      The first list. (Required)
* @param listB      The second list. (Required)
* @param returnListType      Return list type. Values can be: AandB, AorB, AnotB, BnotA  (Required)
* @param listADelimiter      List A delimiter. Defaults to a comma. (Optional)
* @param listBDelimiter      List B delimiter. Defaults to a comma. (Optional)
* @param returnListDelimiter      Return list delimiter. Defaults to a comma. (Optional)
* @return Returns a list.
* @author Christopher Jordan (cjordan@placs.net)
* @version 1, February 14, 2006
*/
function listVenn(ListA,ListB,ReturnListType){
var i                    = "";
var ThisListItem        = "";
var ListBDelimeter        = ",";
var ReturnListDelimeter    = ",";
var ReturnList            = "";
var TempListA            = ListA;
var TempListB            = ListB;

// Handle optional arguments
switch(ArrayLen(arguments)) {
case 4:
{
break;
}
case 5:
{
ListBDelimeter        = Arguments[5];
break;
}
case 6:
{
ListBDelimeter        = Arguments[5];
ReturnListDelimeter = Arguments[6];
break;
}
}
// change delimeters on both lists to match
// couldn't get listchangedelims to work, otherwise I'd have used that.
ListA = "";
ListB = "";
for (i = 1; i lte listlen(TempListA,ListADelimeter); i = i + 1){
ListA = ListAppend(ListA,ThisListItem,ReturnListDelimeter);
}
for (i = 1; i lte listlen(TempListB,ListBDelimeter); i = i + 1){
ThisListItem = listgetat(TempListB,i,ListBDelimeter);
ListB = ListAppend(ListB,ThisListItem,ReturnListDelimeter);
}

// A and B (aka Intersection)
if (ReturnListType eq "AandB"){
for(i = 1; i lte listlen(ListA,ReturnListDelimeter); i = i + 1){
ThisListItem = listgetat(ListA,i,ReturnListDelimeter);
if (ListFindNoCase(ListB,thisListItem,ReturnListDelimeter)){
ReturnList = ListAppend(ReturnList,ThisListItem,ReturnListDelimeter);
}
}
}
// A or B (aka Union)
else if(ReturnListType eq "AorB"){
ReturnList = ListA;
ReturnList = ListAppend(ReturnList,ListB,ReturnListDelimeter);

}
// A not B
else if (ReturnListType eq "AnotB"){
for(i = 1; i lte listlen(ListA,ReturnListDelimeter); i = i + 1){
ThisListItem = listgetat(ListA,i,ReturnListDelimeter);
if (not ListFindNoCase(ListB,thisListItem,ReturnListDelimeter)){
ReturnList = ListAppend(ReturnList,ThisListItem,ReturnListDelimeter);
}
}
}
// B not A
else if (ReturnListType eq "BnotA"){
for(i = 1; i lte listlen(ListB,ReturnListDelimeter); i = i + 1){
ThisListItem = listgetat(ListB,i,ReturnListDelimeter);
if (not ListFindNoCase(ListA,thisListItem,ReturnListDelimeter)){
ReturnList = ListAppend(ReturnList,ThisListItem,ReturnListDelimeter);
}
}
}
return ReturnList;
}

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