Author: Tomas Rutkauskas 

I have a form with checkboxes in 8 rows and 7 columns. I want to be able to 
determine which combinations of rows and columns have been checked off. Is the best 
way to do this using a 2-D array? How would I declare this array for the checkboxes?

Answer:

1   FArray: array[0..7, 0..6] of TCheckBox;
2   
3   //You also you have to create Checkboxes at runtime, like:
4   
5   FArray[i, j] := TCheckBox.Create(Self);
6   
7   I would suggest to use the Tag property instead. Assign the same OnClick event 
8   handler to all checkboxes and code the Tag for each checkbox. Say 23 (second 
9   column, third row), you know like matrix indices in math:
10  
11  ....OnClick(Sender: TObject);
12  var
13    ATag: Integer;
14  begin
15    if (Sender is TComponent) then
16    begin
17      ATag := TComponent(Sender).Tag;
18      ShowMessage(Format('Column %d, Row %d', [ATag div 10, ATag mod 10]));
19    end;
20  end;