Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

vb.net - multi-dimension array list

Tags:

vb.net

I've managed to make some single dimension array lists but I can't figure out a multi dimension arraylist.

Here's what I'm trying to do:

I have a database (mdb) with 5 columns that I want each row to be in an array list.

In PHP what I'd typically do is:

$array[$field1] = array($field2,$field3,$field4,$field5);

How I do the same in vb.net so anytime I need to fetch an item for a specific for the row1 I could call it?

For a single dimension I could do the following, but I can't figure out how to add more fields to a single array row:

    Dim tmpArrayX As New ArrayList
    tmpArrayX.Add(field(0))
    tmpArrayX.Add(field(1))
    etc...
like image 446
Joe Avatar asked Sep 07 '10 13:09

Joe


People also ask

Can an ArrayList be multidimensional?

Overview. Creating a multidimensional ArrayList often comes up during programming. In many cases, there is a need to create a two-dimensional ArrayList or a three-dimensional ArrayList. In this tutorial, we'll discuss how to create a multidimensional ArrayList in Java.

What is multidimensional array in VB?

VB.NET supports two types of multidimensional arrays: rectangular and jagged. In a rectangular array, every row is the same length. In a jagged array, however, each row can be a different length. In fact, you can think of each row in a jagged array as an array unto itself.


2 Answers

If you want to use ArrayList, just make it's items contain other ArrayLists.

Or you could use normal arrays as:

Dim multiArray(2, 2) As String
multiArray(0, 0) = "item1InRow1"
multiArray(0, 1) = "item2InRow1"
multiArray(1, 0) = "item1InRow2"
multiArray(1, 1) = "item2InRow2"

Though my personal preference would be to use List as:

Dim multiList As New List(Of List(Of String))
multiList.Add(New List(Of String))
multiList.Add(New List(Of String))

multiList(0).Add("item1InRow1")
multiList(0).Add("item2InRow1")
multiList(1).Add("item1InRow2")
multiList(1).Add("item2InRow2")

Edit: How to find row:

Dim listIWant As List(Of String) = Nothing
For Each l As List(Of String) In multiList
    If l.Contains("item1InRow2") Then
        listIWant = l
        Exit For
    End If
Next
like image 197
Hans Olsson Avatar answered Oct 10 '22 04:10

Hans Olsson


' This allows adding rows on the fly....Tested and it works!

Dim multiList As New List(Of List(Of String))
Dim ListRow As Integer = 0

For each record in some_source 
  dim Country as string = record.country 'from some source 
  dim Date as Date = record.Date 'from some source 
  dim Venue as string = record.Venue 'from some source 
  dim Attendance as string = record.Attendance 'from some source 

  multiList.Add(New List(Of String))
  multiList(ListRow).Add(Country)
  multiList(ListRow).Add(Date)
  multiList(ListRow).Add(Venue)
  multiList(ListRow).Add(Rating)
  multiList(ListRow).Add(Attendance)
  ListRow = ListRow + 1
next
like image 20
JoeBob Avatar answered Oct 10 '22 02:10

JoeBob