Object Module in VBA As A Container for Constant values? - vba

Question

I am studing VBA object module and trying to use it as an easy way of retriave objects properties.
I write the code below and would really appreciate if you could tell me if there is a better way of doing it, or if I am in the right path for write some good code.
Consider that I intend to use this on a bigger project, so I need to know if it is well written.
Class Module Animals
Option Explicit
Private pCat As New Animal
Private pDog As New Animal
Private pFish As New Animal
Private Sub Class_Initialize()
pCat.Mammal = True
pCat.NumberOfPaws = 4
pDog.Mammal = True
pDog.NumberOfPaws = 4
pFish.Mammal = False
pFish.NumberOfPaws = 0
End Sub
Property Get Cat() As Animal
Set Cat = pCat
End Property
Property Get Dog() As Animal
Set Dog = pDog
End Property
Property Get Fish() As Animal
Set Fish = pFish
End Property
Class Module Animal
Option Explicit
Private nPaws As Integer
Private pMammal As String
Property Get NumberOfPaws() As Integer
NumberOfPaws = nPaws
End Property
Property Let NumberOfPaws(numPaws As Integer)
nPaws = numPaws
End Property
Property Get Mammal() As Boolean
Mammal = pMammal
End Property
Property Let Mammal(IsMammal As Boolean)
pMammal = IsMammal
End Property
Subroutine for testing the object modeules above
Option Explicit
Sub Test()
Dim objAnimal As New Animals
Debug.Print objAnimal.Cat.Mammal
Debug.Print objAnimal.Cat.NumberOfPaws
Debug.Print objAnimal.Dog.Mammal
Debug.Print objAnimal.Dog.NumberOfPaws
Debug.Print objAnimal.Fish.Mammal
Debug.Print objAnimal.Fish.NumberOfPaws
End Sub

Answer 1

If you plan to use a large number of Animal objects, it's wise not to create a new container for them as a new object, but to use a built-in one, like Collection, which has list and dictionary properties. Also you can use a Dictionary object.
It also makes sense to add the Name property to the Animal object to distinguish one object from another in the list. Additionally: you can make it convenient to create objects (like https://stackoverflow.com/a/15224115/15035314), as well as to display information about the object (see the procedure PrintMe()).
Animal class module
Option Explicit
Private mName As String
Private nPaws As Integer
Private pMammal As Boolean
Public Sub InitiateProperties(Name As String, Paws As Integer, Mammal As Boolean)
mName = Name
nPaws = Paws
pMammal = Mammal
End Sub
Public Sub PrintMe()
Debug.Print "The animal is " & mName & ", it has " & nPaws & " paws(s) and is" & IIf(pMammal, " ", " not ") & "a mammal"
End Sub
Property Get Name() As Integer
Name = mName
End Property
Property Let Name(theName As Integer)
mName = theName
End Property
Property Get NumberOfPaws() As Integer
NumberOfPaws = nPaws
End Property
Property Let NumberOfPaws(numPaws As Integer)
nPaws = numPaws
End Property
Property Get Mammal() As Boolean
Mammal = pMammal
End Property
Property Let Mammal(IsMammal As Boolean)
pMammal = IsMammal
End Property
Module1 common module
Option Explicit
' based on https://stackoverflow.com/a/15224115/15035314
Public Function CreateAnimal(Name As String, Paws As Integer, Mammal As Boolean) As Animal
Set CreateAnimal = New Animal
CreateAnimal.InitiateProperties Name, Paws, Mammal
End Function
Sub test()
Dim Animals As New Collection, A As Animal
Animals.Add CreateAnimal("Cat", 4, True), "Cat"
Animals.Add CreateAnimal("Dog", 4, True), "Dog"
Animals.Add CreateAnimal("Fish", 0, False), "Fish"
' and so on
For Each A In Animals
A.PrintMe
Next
Debug.Print "The cat has " & Animals("Cat").NumberOfPaws & " paws" 'get the animal from the collection by name
End Sub
Running test() prints:
The animal is Cat, it has 4 paws(s) and is a mammal
The animal is Dog, it has 4 paws(s) and is a mammal
The animal is Fish, it has 0 paws(s) and is not a mammal
The cat has 4 paws