How can init a class containing an array?

[Marc from D]

Hello!

please help me with my beginners-question:

I try to program a Handball-timer-program. Just for fun, as I want to learn some .net programming using basic.

I want to define my data structures first:
so I created a "player" class, containing string for name and a byte for yellow and red cards.
Also I created a "team"-class, containing a single "player".
The "game"-class contains two "team"-s.

1. question: how can I tell my "team"-class to contain an array of 16 elements of "player"

2. how can I init all fields so they do not contain "NULL" but a valid value, i. e. an empty string as the players name?


Thanks a lot!

Marc

[DDavich]

Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim Game As New Game
        Dim Player As New Player
        For SixteenPlayers As Integer = 1 To 16
            With Game
                .Baseball.BlueJays.Add(Player)
                .Basketball.Raptors.Add(Player)
            End With
        Next
    End Sub 'Break it here and you can see the "Game" object nicely

    Public Class Game
        Public Basketball As New Basketball
        Public Baseball As New Baseball
    End Class

    Public Class Basketball
        Public Raptors As New ArrayList
    End Class

    Public Class Baseball
        Public BlueJays As New ArrayList
    End Class

    Public Class Player
        Public PlayerName As String = ""
        Public PlayerNumber As String
        Public PlayerSucks As Boolean
    End Class

End Class

Here's an example of what I think you might be looking for. As you can see the Game object can grow very quickly and it's very easy to work with for changes etc...

[javajawa]

nice solution.
May I suggest something safer - use the new sub:

Public Class Player
End Class

Public Class Team
    Private mPlayers() As Player
    Private mTeamName As String

    Public Sub New(ByVal TeamName As String, ByVal Players As Integer)
        mTeamName = TeamName
        mPlayers = Array.CreateInstance(GetType(Player), Players) 'This auto-magically create the array structure for a 1-d array of n items of type t...
        For I As Integer = 0 To Players - 1
            mPlayers(I) = New Player()
        Next
    End Sub

    Public ReadOnly Property TeamName() As String
        Get
            Return mTeamName
        End Get
    End Property

    Public Property Player(ByVal Index As Integer) As Player
        Get
            Return mPlayers(Index)
        End Get
        Set(ByVal value As Player)
            mPlayers(Index) = value
        End Set
    End Property
End Class

[Marc from D]

Thanks a lot! I will try both ways later, when it is late evening here in germany.

But please -if possible- give me a hint why it is forbidden to do something like this in a class:

class player
dim x as string
...
end class

class team
dim Teammember(16) as player
...
end class

I think, that the compiler knows everything it takes to create the machine code. But it is not willing to initialize an array with a given size.What is the advantage of an arraylist compared to a plain array?

You see, I'm just wondering.

Again: Thanks alot for the already given code and hints.


Marc

[javajawa]

You can do that:

Public Class Test
  Dim A(16) as Whatever
  Dim X as String
End Class

It works just fine here.
But defining an array only reserves the space in memory - it doesn't initialise the variables if they are user defined. This has to be done manually, either by using "New Whatever()" on each element, or using the array's Initialise sub routine.