Sort array problem (VB)

[phillip]

I have an array containing letters and numbers that im trying to sort.

 

using the array sort method i'm not geting the results im after

 

Example

 

A1

A2

A3

A4

A5

A6

A7

A8

A9

A10

A11

A20

 

Is being sorted.

 

A1

A10

A11

A2

A20

A3

A4

A5

A6

A7

A8

A9

Edited April 3, 2006 by phillip

[mskeel]

It looks like the sort method is sorting the entries as strings (alphabetical order where 10 comes before 9). There is a sort method for the Array Class that takes an IComparer as an argument. It looks like you'll have to write a class that impliments the IComparer interface to get the desired sort that you want. There is tons of good info on the internet to help you out.

 

Here's some MSDN info on the method you want with a mediocre example. That should be enough to get you started.

[PlausiblyDamp]

The sort function is sorting them correctly based on the elements being strings. If you desire a different sort order then you might want to look at creating a customised implementation of IComparer.

 

The following snippet should give you a basic idea.

 

Class Testing
   Implements IComparer

   Public Function Compare(ByVal x As Object, ByVal y As Object) As Integer Implements System.Collections.IComparer.Compare
       Dim x1 As String, y1 As String
       x1 = DirectCast(x, String)
       y1 = DirectCast(y, String)

       Dim i1, i2 As Integer

       i1 = Integer.Parse(x1.Substring(1))
       i2 = Integer.Parse(y1.Substring(1))

       If i1 > i2 Then Return 1
       If i1 < i2 Then Return -1
       Return 0


   End Function
End Class

 

This can then be called from a method like

   Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
       Dim a() As String = {"a1", "a10", "a3"}

       Dim x As IComparer

       Array.Sort(a, New Testing)

   End Sub