Delphi - FindComponent

 procedure TForm1.Button1Click(Sender: TObject);
var
  i : Integer;
begin
  for i := 1 to 3 {Anzahl Edits} do
  begin
    with TEdit(FindComponent('Edit'+IntToStr(i))) do
    begin
      if Text = '' then ShowMessage('Edit'+IntToStr(i)+' ist leer');
    end;
  end;
end;