Representing multiple items with a single value?

Donny Bahama · January 16th, 2006, 08:26 PM

I don't know the proper term for it, but there's a methodology in which items are assigned a value, and the value representing each successive item is double that of the last...

Item1 = 1
Item2 = 2
Item3 = 4
Item4 = 8
Item5 = 16
Item6 = 32
Item7 = 64

such that a value of 65 can only be a combination of Items 1 and 7. The only way I can think of decoding the combined value is using a [code language=vbscript]Select Case[/code] statement, but in the example above, 127 cases would be required. There has to be a better way! Can someone please point me toward it?

Donny Bahama · January 16th, 2006, 09:32 PM

Figured it out - needed to use a bitwise comparison. Here's the code in case it helps anyone...

Code:

' Item 1 = 1
' Item 2 = 2
' Item 3 = 4
' Item 4 = 8
' Item 5 = 16
' Item 6 = 32
' Item 7 = 64
x = InputBox("Enter a number between 1 and 127...")
items = "init"
If (x AND 1) = 1 Then
    items = "Item 1"
End If
If (x AND 2) = 2 Then
    If items = "init" Then
        items = "Item 2"
    Else
        items = items & ", Item 2"
    End If
End If
If (x AND 4) = 4 Then
    If items = "init" Then
        items = "Item 3"
    Else
        items = items & ", Item 3"
    End If
End If
If (x AND 8) = 8 Then
    If items = "init" Then
        items = "Item 4"
    Else
        items = items & ", Item 4"
    End If
End If
If (x AND 16) = 16 Then
    If items = "init" Then
        items = "Item 5"
    Else
        items = items & ", Item 5"
    End If
End If
If (x AND 32) = 32 Then
    If items = "init" Then
        items = "Item 6"
    Else
        items = items & ", Item 6"
    End If
End If
If (x AND 64) = 64 Then
    If items = "init" Then
        items = "Item 7"
    Else
        items = items & ", Item 7"
    End If
End If
MsgBox items