There isn't one. Delphi components do not have an Index property like VB
controls, so you can't declare an array of them. However, there are three
main reasons why you might want to, and each of them can be done in Delphi.
Here's how:
Reason 1. You want to share event handlers between different controls on a
form.
This is really easy. All you have to do is select the same event handler
procedure in each of the controls' events. This is better than control
arrays because you can even have the same event handler function across
different kinds of control; for example, a toolbar button and a menu item
can call the same function directly in each of their Click events.
Reason 2. You want to be able to dynamically allocate and deallocate
controls at run-time.
This is also pretty easy in Delphi. Suppose you have a button on a form,
and each time it is clicked, you want to create another, different button.
The following sample code shows how to do this:
procedure TForm1.Button1Click(Sender: TObject);
var
NewButton: TButton;
begin
NewButton := TButton.Create(Self);
NewButton.Parent := Self;
end;
It is important to note that once this event finishes, the NewButton
variable goes out of scope and we no longer have a pointer to the newly-
created control. You can't deallocate a control within its own event
handlers, so if at some point you want to remove one or more dynamically-
created controls, you have to search for them in the Form.Controls array
and/or maintain your own list of pointers to the controls you create.
Assuming that there are no control event handlers running, it is safe to
deallocate a control by just calling its Free method.
Reason 3. You really want to access controls by number.
I ran across this when I decided to write a board game similar to Reversi
as a Delphi learning project. I had 100 TShape controls on a form, in a
10x10 grid. So, I painted all the shapes in the form designer and allowed
it to give them names like "ShapeNN", but then I also declared an array of
pointers to controls: "Board: array[1..10, 1..10] of ^TShape;" and
populated it in the form's Create event. This is a hundred lines of code
that really shouldn't be necessary, but from then on I could access
controls in a two-dimensional array, like this: "Board[3,5]^.Brush.Color :=
clRed;" -- which is more than I could have done with VB.