Question

Which is generally fastest when reading/comparing row info from a DataTable?

'assume dt as datatable'  'method 1' dim i as int32 for i = 0 to dt.rows.count - 1    .... next  'method 2' dim row as datarow for each row in dt.rows     .... next 

And if there’s a difference, in what circumstances does it pay to use one over the other?

Thanks in advance for any guidance!

Answer 1

The compiler expands For Each to a short while loop.

for each row in dt.rows // expands to: IEnumerator e = dt.rows.GetEnumerator() while e.MoveNext()     row = e.Current 

So you pay a small amount of overhead. But for clarities sake, I’d still stick with For Each if you’re only working on one row, and you aren’t modifying the data set.