doingsoftware

In the highschool I’ve had a very good programming teacher. I remember her ‘famous’ quote – ‘keep your mind awake!’ (she liked so much this quote, that she was telling it several times on each curse). At that time I didn’t understand how true it was. Today I’ve had some free time and I remembered that I haven’t work for several months with recursion, so why not to make a small exercise? First component I’ve saw on the project I’m working it was a TMainMenu component. Simply, get with a recursion function, all items captions from a menu.

On a form, drop a TMainMenu component, and set several menu items. Also, drop a TMemo component on the form. Exercise is very simple: list on the TMemo all the menu’s items names. First time by using loops (choose from ‘for’, ‘while’ or ‘repeat’ – explication for each one of them can be found here) and second time by using recursion! In 5-10 minutes you should finish this exercise. Below is how I’ve resolved it. If you have find a better way, shout

procedure GetItemsCaption;
var wi:Integer;
    wj:Integer;
begin
 for wi:=MainMenu1.Items.Count-1 downto 0 do
  if MainMenu1.Items[wi] is TMenuItem then
   begin
    Memo1.Lines.Add( TMenuItem(MainMenu1.Items[wi]).Caption);
    For wj:=TMenuItem(MainMenu1.Items[wi]).Count-1 downto 0 do
     Memo1.Lines.Add( TMenuItem(MainMenu1.Items[wi]).Items[wj].Caption);
  end;
end;


{recursion function bring it on!!!!}
procedure GetRecursiveItemsCaption;
var wj:Integer;

 function GetMenuItems(aMenuItem:TMenuItem):TStringList;
  var wi:integer;
  begin
   Memo1.Lines.Add(aMenuItem.Caption);
   wi:=aMenuItem.Count-1;
    while wi>=0 do
     begin
      GetMenuItems(aMenuItem.Items[wi]);
      dec(wi);
     end;
  end;//GetMenuItems ends here

//body of a function/procedure from your form
begin
//first on the 'loop' style

 procedure GetItemsCaption;

 Memo1.Lines.Add('recursion');
//'recursive' style

 For wj:=MainMenu1.Items.Count-1 downto 0 do
  GetMenuItems(MainMenu1.Items[wj]);
end;

Is better sometimes to make this kind of exercises to remember some basic stuff.