Collections vs Arrays

[AaronL]

Hello,

I need help determining what the best way to store properties of multiple items.

For example, I am creating a list box and every item in the list box needs to have properties. I don't want to use arrays because I'm not going to know the maximum items in the list box. I read briefly on Microsoft's site about "collections" but I don't quite understand how they are used. Can someone give me an example of what I would do as far as code.

Thanks!

[debasisdas]

collection is the best solution for your case.

you just need to create an use defined type and use that.

[AaronL]

I'm not sure how to use collections, can you give me some code examples??

[rpicilli]

This is how to use a collection or list of


[code]

Dim myList as new List(Of String)

myList.Add("Something")
myList.Add("Other thing no matter what the size is")

/[code]

Tell me if this help you

[AaronL]

Ok, it helps a little, but how to you have multiple fields in a list for example, if I were to create a list that had

Name
Address
Phone Number
Email

I would want all of those in different fields and reference them somewhat like this

MyList.Name(index number)

or something of that sort, how would I do that? Or do I have to use delimiters in the string??

[AaronL]

Also, I want to make my own database, is this the best way to do this in VB6??

[rpicilli]

Hi Chelf

You want to create a database this is not the best way. Try to use a table.

About your first question you can use struture and keep it into the List of string.

Create a new project and put in a form just one buttom.

Copy this code and try to understand it.

[code]
Public Structure Customer
Public name As String
Public age As Integer
Public address As String
Public gender As String
End Structure
Dim myList As New List(Of Customer)

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
'Instanciate a structure
Dim CurCustomer As Customer
'Put some information on the structure
CurCustomer.name = "John"
CurCustomer.age = 24
CurCustomer.address = "Some address"
CurCustomer.gender = "Male"
'Save in the list
myList.Add(CurCustomer)
End Sub
/[code]

I hope this help you

[AaronL]

That's great!! Thank you for your help. Now you mentioned that this isn't the best way to make a database? What do you recommend as far as designing your own database, I don't want to use SQL etc.. I want this to be proprietary...

[rpicilli]

Ok, if you want to make your data proprietary, you'll need to do by yourself.

In the current market if you intend to create a commercial product, you'll repel your possible customer as soon as they know about proprietary data.

Think about it.

Rpicilli

[AaronL]

I'm using VB6 and I noticed that Structure and List doesn't work with it, I figured out how to make a new structure with the Type declaration but how do I do the List using the Collection declaration? I noticed I can't use Dim MyList as New Collection(Of Type) it says expected end of statement

[rpicilli]

Hi,

Excuse me by this. I don't have the VB6 and I don't remember how to do that. I'll try to figured out and let you know.

Rpicilli

[AaronL]

Does anyone know what I'm doing wrong?

Public Type UserData
ID As String
Password As String
End Type
Public User As UserData
Public UserFile As Collection

Shouldn't I be able to do something like

UserData.ID = "username"
UserData.Password = "password"
UserFile.Add(User)

I get some weird message about data types being coerced or something stupid. I just want to make a simple collection instead of using an array, why is this so hard to do?