Question

EDIT

Ok, so after working through this for a while, I’ve come up with a solution that works, and it’s cleaner than I had originally thought up for it. Thanks for the help guys. Here’s the code.

Function Program_Search() As String()
    'An ArrayList of Objects containing strings for each row.
    'So the result is ArrayList(objRow1(strID, strPrograms), objRow2(strID, strPrograms).. etc)
    Dim program_results As ArrayList = Get_Results("SELECT ID, Programs FROM tbMetrics ORDER BY ID ASC", strConnectionString)

    'Initialize the list of programs. This will contian the tbMetrics Programs that match the selected Program name.
    Dim programs As ArrayList = New ArrayList

    'Loop through each row selected
    For Each row As Object In program_results
        'Not currently used.
        Dim strID As String = row(0).ToString

        'An integer representation of a binary number. Each digit represents a different program being checked.
        Dim intPrograms As Integer = CInt(row(1).ToString)

        'Convert number to binary string (reversed)
        Dim strReversed As String = StrReverse(Convert.ToString(intPrograms, 2))

        'Loop through each of the programs in the drop down box which should contain all of the possible choices in order.
        For index As Integer = 0 To ddlPrograms.Items.Count - 1
            'A bit of an ugly if state that checks for a 1 in the binary position for the selected program.
            'Then if it's selected, it checks that the program matches the one selected by the user.
            'Finally, it makes sure it doesn't add the same number to the array.
            If (strReversed.Length - 1) >= index _
                And strReversed(index) = "1" _
                And ddlPrograms.SelectedValue.ToString = ddlPrograms.Items(index).Value.ToString _
                And programs.Contains(intPrograms) = False Then

                'If it passes all of the above checks, then finally add the program integer to the arraylist.
                programs.Add(intPrograms)
            End If
        Next index
    Next row

    'Return the list of programs as an array, to be used with SQL IN().
    Return programs.ToArray
End Function

END EDIT

ORIGINAL BELOW

Ok, so I’m a PHP programmer, trying to learn some VB.NET. Arrays greatly confuse me in VB.NET, so I wrote some example code in PHP the way I know how to do it. I would greatly appreciate it if someoen could show me the proper way it would work in VB.NET.

<?php

function get_result() {
    $result = query("SELECT id, value FROM test_table");
    /*Returned as:
    array(
      array("id1", "value1"), 
      array("id2", "value2")...etc.
    )*/

    $haystack_top = array();

    foreach ($result as $row) {
        $id = $row[0]; //Not used currently
        $value = $row[1];

        for($i=0; $i <= $value; $i++) {
            if (check_value($i)) {
                $haystack_value = get_new_value($i);
                $haystack_top[$value][] = $haystack_value;
            }
        }
    }

    $needle = get_needle();

    $result = array();

    foreach ($haystack_top as $value=>$haystack) {
        if (in_array($needle, $haystack)) {
            $result[] = $value;
        }
    }

    return array_unique($result);
}

?>

Here’s an older, unfinished copy of what I’ve been working on in Vb.NET It’s not in the form I actually need because I changed how the logic should work while building the PHP example, but it shows the confusion I ran into with Arrays in VB.NET.

Function Program_Search() As String()
    Dim program_results As Object = Get_Results("SELECT ID, Programs FROM tbMetrics ORDER BY ID ASC", strConnectionString)

    'Create an array of strings to fill with potential field results.
    Dim fields As List(Of String) = New List(Of String)()

    For Each row As Object In program_results
        Dim strID As String = row(0).ToString
        Dim strPrograms As String = row(1).ToString

        Dim intPrograms As Integer = CInt(strPrograms)

        'Convert number to binary string (reversed)
        Dim strReversed As String = StrReverse(Convert.ToString(intPrograms, 2))

        For index As Integer = 0 To ddlPrograms.Items.Count - 1
            If (strReversed.Length - 1) >= index Then
                If strReversed(index) = "1" Then
                    fields.Add(ddlPrograms.Items(index).Value.ToString)
                End If
            End If
        Next index
    Next row

    Dim programs As String() = fields.ToArray

    Dim results As String()

    If programs.Contains(ddlPrograms.SelectedValue.ToString) Then

    End If

    Return programs
End Function

Because someone was curious about the Get_Results function here’s the code for that.

'Runs the passed query and returns each row as an object within an ArrayList
    Function Get_Results(ByVal query As String, ByVal ConnectionStringName As String) As ArrayList
        Dim sqlComm As Data.SqlClient.SqlCommand = Get_Connection(query, ConnectionStringName)

        'Open that connection
        sqlComm.Connection.Open()

        'Execute the query and store all of the results into the SqlDataReader.
        Dim sqlRead As Data.SqlClient.SqlDataReader = sqlComm.ExecuteReader()

        Dim result As ArrayList = New ArrayList

        'Read each row one by one.
        While sqlRead.Read()
            'Create an object of the size needed.
            Dim row(sqlRead.FieldCount - 1) As Object

            'Fill the row object with the values.
            sqlRead.GetValues(row)

            'Add the result object to the array.
            result.Add(row)
        End While

        'Close all open connections to the database.
        sqlRead.Close()
        sqlComm.Connection.Close()

        Return result
    End Function

Answer 1

Based on this comment “…to be honest, I’m just confused how to properly create dynamic multi-dimensional arrays in VB.NET, and how to use them like I do in my PHP example…”, I’ll provide my answer.

Your line:

 Dim fields As List(Of String) = New List(Of String)()

creates a list, not an array. Lists are a bit easier to use as you can add items without having to resize. You could make a List(Of MyObject) if you would like to do that instead of a 2D array. Just create a class with two fields and make a list of those objects. Your class would be about 4 lines of code.

To create a 2D array, which is what it looks like you’re doing, you should find everything you need here.

http://msdn.microsoft.com/en-us/library/d2de1t93(v=vs.90).aspx

Unfortunately, to create a dynamic 2D array, there’s no streamline way to do that. You have to copy the elements over to another array, if I’m not mistaken. It’s pretty lame, I know. That’s why I like the List(Of MyObject) approach in that you can just MyList.Add(myObject) when you create a new item.

If you need to iterate through the items later to retrieve the values, you can just use a for-loop and access them as such:

MyList(i).MyObjectPropertyName1
MyList(i).MyObjectPropertyName2

VB.NET is probably one of the more readable languages, but with any, you have to get used to it. I looked at your PHP and my head almost exploded. I’m sure if I took a couple hours and learned the syntax, it’d make (more) sense.