[RESOLVED] Dynamic array related question

[david_707]

Hi folks!

I know how to work with fixed arrays, but I would like to make it more clear and ask a question regarding fixed arrays. For example, what's the difference when declaring:

Dim str(0 to 100) as string

and

Dim str (100) as string

Is it just for specify the lower limit of the array or there is another explanation?

The main question is about Dynamic arrays. I usually work with Winsock and I never know the data arrival how many strings will provide. For example:

Dim str() as string

Then when doesn't know the dimension, how to allocate the actual number of elements with a ReDim statement??

Redim str(???) as string?? Or should i write the supposed value for it? That every time can exceed the limit?

Thanks in advance

[RhinoBull]

Yes, whenever you need to dimension array you can use either Redim or Redim Preserve statement - kim that Redim Preserve may be slow depending on array size.
Redim clears the array sets new dimension and Redim Preserve keeps all current values and also sets new dimension.

Typically you would initialize array with one element Redim myArray(0) As String.
Every time you need to populate it you can use Ubound function:

myArray(Ubound(myArray)) = "abc"
Redim Preserve myArray(Ubound(myArray) + 1)

[Bobbles]

I have not worked with Winsock, so I don't know how the data (strings) look, and what the delimiters will be like.
But it is possible you could use one the useful features that VB6 introduced - Split
What that does is split the contents of a string variable into elements in an array. You have to tell it what the delimiter is that it will use to 'divide' the string into the elements of the array.
Here is an example -

Option Explicit

Private Sub Form_Click()
 Dim sArr() As String
 Dim sData As String
 Dim i As Integer
    sData = "AA, BB, CC, DD, EE, FF, GG"
    sArr = Split(sData, ",")
    For i = 0 To UBound(sArr)
        Debug.Print Trim(sArr(i))
    Next i
End Sub

[dilettante]

And if you need a different lower bound value Redim accepts that too.

For these sorts of questions you ought to check the manual first. There are lots of factors involved and nobody is going to cover them exhaustively in a forum post.

[david_707]

Dear Bobbles

I'm talking about Chat clients, thay get every time new data, like users, direct messages or main screen messages. So, the split function helps me to divide username and its icon and put them on listview. For example, a listview that has one subitem for usernames and other one displaying icons of each user. So, for the chat messages and users, I need to preserve data and each time appears new message, add this message to the existing data without losing data

Dear RhinoBull

Thanks a lot, that' what I need exactly! Much appreciated

Well dilettante

If i don't read the tutorial I would never know the type of arrays and their composition. But sometimes the tutorials doesn't contain everything. I may read 1, 2, 3 and get an idea but always is better when someone is able to explain all doubts within a simple and clear post like RhinoBull did.

Thanks!