title: How to copy value of one data column into another data column in the same data table C#?
body: <p>I want to copy <code>itemarray[4]</code> of datatable to <code>itemarray[6]</code> of that datatable. I used this code and I didn’t see any changes:</p>
  
  <pre><code>foreach (DataRow dr_row in dt_table.Rows)
  {
      foreach (var field_value in dr_row.ItemArray)
      {
          object cell_data = field_value;
          if (dr_row.ItemArray[6].ToString() == "")
          {
              dr_row.ItemArray[6] = dr_row.ItemArray[4];
          }
          original_data += cell_data.ToString();
      }
      original_data += Environment.NewLine;
  }
  </code></pre>