Steps to modify data in a DataTable

Suppose we have a DataTable with columns Name,Age, Status

  //DataTable dtRecords;
      DataRow[] rows = dtRecords.Select();
          if (rows != null && rows.Length > 0)
          {
              foreach (DataRow row in rows)
              {
                  if (Convert.ToInt16(row["Age"]) > 18 )
                  {
                      row["Status"] = "Can Vote";
                 }
              }
          }
 

OR
you can also select specific rows then work accordingly

              string name = "xxx";
              DataRow[] rows = dtRecords.Select("Name = " + name);
            if (rows != null && rows.Length > 0)
            {
                foreach (DataRow row in rows)
                {
                    lblName.Text = Convert.ToString(row["Name"]);
                }
            }