DataTable & Row Number Question

[RhythmAddict112]

Hey boys 'n girls -
Real quick Q..

Formally, I was coding my loop through a data table like...

        Dim s As New List(Of String)(dt.Rows.Count)
        Dim dr As DataRow
        For Each dr In dt.Rows
            s.Add(dr("FirstName").ToString)
        Next
        Return s.ToArray

However...I need to exit my for loop when I hit 5 rows. As a quick fix I'm doing it like this...

        Dim s As New List(Of String)(dt.Rows.Count)
        For i As Int16 = 0 To dt.Rows.Count - 1
            If i > 4 Then Exit For
            s.Add(dt.Rows(i).Item(0))
        Next

So my question...is the 2nd way much worse/less performant/messier than the first? Is there an easy way for me to get the row number in the first method? Thanks!

http://geekswithblogs.net/sanjayu/

 

[RiverGuy]

The only other way I can think of to do what you are looking to do is as follows:

Dim s As New List(Of String)(dt.Rows.Count)
Dim i As Integer = 0
For Each dr In dt.Rows
  i += 1
  If i > 4 Then Exit For
  s.Add(dr("FirstName").ToString)
Next

However, there's not much difference compared with what you have suggested already. As far as performance impact, you'd probably just want to test both blocks of code and see if one runs consistently faster.