Dataset table rows

The DataSet object has a Tables array. If you know the table you want, it will have a Row array, each object of which has an ItemArray array. In your case the code shown below , would give you the item at zeroth position means the very first item in the first row.

int var1 = int.Parse(ds.Tables[0].Rows[0].ItemArray[4].ToString());

You can also use Columns instead of ItemArray and specify the column name as
a string instead of remembering it's index. That approach can be easier
to keep up with if the table structure changes. So that would be

int var1 = int.Parse(ds.Tables[0].Rows[0]["MyColumnName"].ToString());