[RESOLVED] Classes

[Milk]

A UDT provides a way of grouping several variables together under one name. Generally speaking a UDT is handled just like any other variable. UDT's can be nested i.e. one of a UDT's subtypes could be another UDT.

A Class describes an object. A Class can be used in a similar way to a UDT but it can also do a lot more, eg have it's own methods properties etc. A Form is a class.

Here is an example of how you could (but wouldn't) define a team as an object

Option Explicit

Public Name As String
Public Batting As Integer
Public DefRating As Integer
Public Position As Integer

Private cThrowArm As Integer

Public Property Get ThrowArm() As Integer
    ThrowArm = cThrowArm
End Property

Public Property Let ThrowArm(value As Integer)
    If value > 80 Then
        value = 80
    ElseIf value < 10 Then
        value = 10
    End If
    cThrowArm = value
End Property

Private Sub Class_Initialize()
    Debug.Print "I'm alive!"
End Sub

Private Sub Class_Terminate()
    Debug.Print "Bye!"
End Sub

...and how you might then use it...

Option Explicit
Private mTeams() As cTeam

Private Sub Form_Load()
    ReDim mTeams(3)
    Set mTeams(0) = New cTeam 'creates a new instance of the class
    
    With mTeams(0)
       .Name = "thing"
       .DefRating = 32
       .ThrowArm = 99
    End With
    
    Set mTeams(1) = mTeams(0) 'creates a second reference the 1st team
    
    Debug.Print mTeams(1).DefRating
    Debug.Print mTeams(1).ThrowArm

    set mteams(1) = nothing 'destroys said reference
End Sub

Note how Throwarm has some restrictions as to what values can be set to it.

Classes are a lot slower than UDT's but much more powerful.