How can I determine the position of a particular string in an Array?

 A very simple way of determining whether or not a string exists in an array is to use a loop to check each element:

Dim iLoop, iPos
iPos = -

For iLoop = LBound(SomeArray) to UBound(SomeArray)
If CStr(SomeString) = CStr(SomeArray(iLoop)) then
'We found the element
iPos = iLoop
End If
Nex

iPos will equal the position that SomeString was found in SomeArray; or, if the string was not found in the array, iPos will equal -1.

The following function can be used to quickly determine the position that an element exists in an array:

Function PositionInArray(aMyArray, strLookingFor, compare)
'Return the position strLookingFor is found in aMyArray... if
'strLookingFor is not found, -1 is returned

Dim iUpper, iLoop
iUpper = UBound(aMyArray)

For iLoop = LBound(aMyArray) to iUpper
If compare = vbTextCompare then
If CStr(UCase(aMyArray(iLoop))) = CStr(UCase(strLookingFor)) then
PositionInArray = iLoop
Exit Function
End If
Else
If CStr(aMyArray(iLoop)) = CStr(strLookingFor) then
PositionInArray = iLoop
Exit Function
End If
End If
Nex

'Didn't find the element in the array...
PositionInArray = -

End Function

NOTE: The function expects three parameters:

Here is an example program for the above function:

<%
'******* INCLUDE ABOVE FUNCTION IN CODE HERE *********

Dim aSomeArray
aSomeArray = Array("I", "think", "APlus.Net", "is", "cool!"

Response.Write PositionInArray(aSomeArray, "I", vbBinaryCompare) & "<BR>"
Response.Write PositionInArray(aSomeArray, "foo", vbBinaryCompare) & "<BR>"
Response.Write PositionInArray(aSomeArray, "ASP", vbBinaryCompare) & "<BR>"
Response.Write PositionInArray(aSomeArray, "bar", vbBinaryCompare) & "<BR>"
Response.Write PositionInArray(aSomeArray, "Cool!", vbTextCompare) & "<BR>"
%>

Output is:
0
-1
2
-1