[VB.Net] Overloading a class' Constructor - Tilted Forum Project Discussion Community

Moskie · 06-25-2005, 06:37 AM

I want to write a class that was two different constructors. One version of the constructor takes a string parameter, the other thakes an array of strings. My plan was to have the first version *create* an array of strings of size one (containing the one string that was passed in), then call the other constructor with it.

However, two things stand in my way:

I can't create the array on the fly, so I can't make the constructor call in one line.
The compiler only allows a constructor call from another constructor when it is done on the first line of the function, so I can't create the array beforehand.

So, what am I left to do? Is my only option to fully write out what I want each constructor to do? I suppose I could have them both call a utility function to do what has to be done... but this is kinda annoying. I guess my problem is that I don't see why this can't be done... seems like a basic thing.

Here's an example of what I'm trying to do (just doing this shorthand, might have syntax errors)...

Constructor that takes array:

Code:

Public Sub New(ByVal myStrings() as String)
     'Do stuff
End Sub

First option, create string array before hand:

Code:

Public Sub New(ByVal myString as String)
    Dim temp() as String = { myString }
    Me.New(temp)
End Sub

Won't compile! Constructor call only allowed on the first line... why the hell does it care if someting is done before hand?

And the second option is to somehow make that array and do the call in one line to get around the issues.

Well, more of rant than anything else, I guess. Any thoughts?

asshopo · 06-25-2005, 09:09 AM

Here is the answer you are lookin for

Code:

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        mysub("asdf")
    End Sub

    Public Sub mysub(ByVal myStrings() As String)
        'Do stuff
    End Sub

    Public Sub mysub(ByVal myString As String)
        Me.mysub(New String() {myString})
    End Sub

Moskie · 07-01-2005, 02:52 AM

For some reason, I've never known that you could do: Me.mysub(New String() {myString}) I've tried and tried to create arrays on the fly, and I guess I've never typed it like that. I think I might have been putting an equals sign in there, as in Me.mysub(New String() = {myString})

*sigh*.... why oh why can't my job just let me do C#?

thanks.

asshopo · 07-01-2005, 05:31 AM

Heh, yes, c# would be much better, thats all I use, but many more people know VB(.NET).

06-25-2005, 06:37 AM	#1 (permalink)
Moskie Pure Chewing Satisfaction Location: can i use bbcode [i]here[/i]?	[VB.Net] Overloading a class' Constructor I want to write a class that was two different constructors. One version of the constructor takes a string parameter, the other thakes an array of strings. My plan was to have the first version create an array of strings of size one (containing the one string that was passed in), then call the other constructor with it. However, two things stand in my way: I can't create the array on the fly, so I can't make the constructor call in one line. The compiler only allows a constructor call from another constructor when it is done on the first line of the function, so I can't create the array beforehand. So, what am I left to do? Is my only option to fully write out what I want each constructor to do? I suppose I could have them both call a utility function to do what has to be done... but this is kinda annoying. I guess my problem is that I don't see why this can't be done... seems like a basic thing. Here's an example of what I'm trying to do (just doing this shorthand, might have syntax errors)... Constructor that takes array: Code: Public Sub New(ByVal myStrings() as String) 'Do stuff End Sub First option, create string array before hand: Code: Public Sub New(ByVal myString as String) Dim temp() as String = { myString } Me.New(temp) End Sub Won't compile! Constructor call only allowed on the first line... why the hell does it care if someting is done before hand? And the second option is to somehow make that array and do the call in one line to get around the issues. Well, more of rant than anything else, I guess. Any thoughts? __________________ Greetings and salutations.

07-01-2005, 02:52 AM	#3 (permalink)
Moskie Pure Chewing Satisfaction Location: can i use bbcode [i]here[/i]?	For some reason, I've never known that you could do: Me.mysub(New String() {myString}) I've tried and tried to create arrays on the fly, and I guess I've never typed it like that. I think I might have been putting an equals sign in there, as in Me.mysub(New String() = {myString}) sigh.... why oh why can't my job just let me do C#? thanks. __________________ Greetings and salutations.

07-01-2005, 05:31 AM	#4 (permalink)
asshopo Insane Location: Michigan	Heh, yes, c# would be much better, thats all I use, but many more people know VB(.NET). __________________ Patterns have a habit of repeating themselves.