Class Modules in VBA: Object-Oriented Programming for Advanced Users

Model domain concepts with properties and methods.

Define a class

Insert → Class Module (e.g., CInvoice)

' CInvoice.cls
Option Explicit
Private pNumber As String
Private pAmount As Double

Public Property Get Number() As String: Number = pNumber: End Property
Public Property Let Number(ByVal v As String): pNumber = v: End Property

Public Property Get Amount() As Double: Amount = pAmount: End Property
Public Property Let Amount(ByVal v As Double): pAmount = v: End Property

Public Function Net(ByVal vat As Double) As Double
    Net = Amount / (1 + vat)
End Function

Use the class

Sub Demo()
    Dim inv As CInvoice: Set inv = New CInvoice
    inv.Number = "2025-001": inv.Amount = 119
    Debug.Print inv.Net(0.19)
End Sub