Using Collections in Access VBA - excel

Question

I have this following subroutine In Access VBA:
Sub SampleReadCurve()
Dim rs As Recordset
Dim iRow As Long, iField As Long
Dim strSQL As String
Dim CurveID As Long
Dim MarkRunID As Long
Dim MaxOfMarkAsofDate As Date
Dim userdate As String
CurveID = 15
Dim I As Integer
Dim x As Date
userdate = InputBox("Please Enter the Date (mm/dd/yyyy)")
x = userdate
For I = 0 To 150
MaxOfMarkAsofDate = x - I
strSQL = "SELECT * FROM VolatilityOutput WHERE CurveID=" & CurveID & " AND MaxOfMarkAsofDate=#" & MaxOfMarkAsofDate & "# ORDER BY MaxOfMarkasOfDate, MaturityDate"
Set rs = CurrentDb.OpenRecordset(strSQL, Type:=dbOpenDynaset, Options:=dbSeeChanges)
If rs.RecordCount <> 0 Then
rs.MoveFirst
rs.MoveLast
Dim BucketTermAmt As Long
Dim BucketTermUnit As String
Dim BucketDate As Date
Dim MarkAsOfDate As Date
Dim InterpRate As Double
BucketTermAmt = 3
BucketTermUnit = "m"
BucketDate = DateAdd(BucketTermUnit, BucketTermAmt, MaxOfMarkAsofDate)
InterpRate = CurveInterpolateRecordset(rs, BucketDate)
Debug.Print BucketDate, InterpRate
End If
Next I
End Function
This subroutine put outs a 2x2 list of 76 numbers, consisting of a date and an associated rate. I want to store this list of values as a Collection, so that I can use it as an input in another function. Is it possible to use collections to do this? What would be the appropriate syntax?

Answer 1

I agree with comments that a data dictionary is probably the way to go. The reason is that with a dictionary you can actually loop through the keys if needed. You will need to add a reference to the Microsoft Scripting Runtime. Here is a brief example:
Public Function a()
Dim dRates As New Scripting.Dictionary
Dim key As Variant
dRates.Add #1/1/2016#, 1
dRates.Add #2/1/2016#, 1.5
dRates.Add #3/1/2016#, 2
'You can either access the rate directly with the key:
Debug.Print dRates(#2/1/2016#)
'Or you can loop through the keys/values
For Each key in dRates.Keys
Debug.Print key & " - " & dRates(key)
Next
'Or, you can pass the entire collection to a function
Call b(dRates)
End Function
Public Function b(d As Scripting.Dictionary)
For Each key In d.Keys
Debug.Print key & " - " & d(key)
Next
End Function
This will provide the following output:
1.5
1/1/2016 - 1
2/1/2016 - 1.5
3/1/2016 - 2
1/1/2016 - 1
2/1/2016 - 1.5
3/1/2016 - 2