Recursive Procedure on Delphi.

Yup, recursive procedure (not recursive function, :) ).

I use it to create a simulation about digital asynchronous binary n-bit counter, complete with the denary representation.

n-bit means it's very flexible, you can change n and its output (stringgrid, thats it) automatically adjust itself, :)

Here's the code

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Buttons, Grids, math;

type
  TForm1 = class(TForm)
    StringGrid1: TStringGrid;
    BitBtn1: TBitBtn;
    function denary:integer;
    function tostring(a:boolean):string;
    procedure counter(m:integer);
    procedure proses;
    procedure isiStringgrid;

    procedure BitBtn1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

const n=3;
var
  Form1: TForm1;
  Q:array[0..(n-1)]of boolean;
  clock:boolean=true;
  l,denary:integer;
  running:boolean=false;
implementation

{$R *.dfm}
function tform1.denary:integer;
var i,j:integer;
begin
  j:=0;
  for i:=0 to n-1 do begin
    j:=j+round(power(2,i))*strtoint(tostring(Q[i]));
  end;
  denary:=j;
end;

function tform1.tostring(a:boolean):string;
begin
{}
  tostring:=inttostr(-1*strtoint(booltostr(a)))
end;
procedure tform1.counter(m:integer);
begin
  if l<=n-1 then begin
    Q[l]:=not Q[l];
    if Q[l]=false then begin
       l:=l+1;
       counter(l);
    end;
  end;
end;
procedure tform1.proses;
begin
  clock:= not clock;
  if clock=false then begin
    l:=0;
    counter(l);
    isiStringgrid;
  end;
  stringgrid1.Cells[1,1]:=tostring(clock);
end;

procedure tform1.isiStringgrid;
var i:integer;
begin
  for i:=0 to n-1 do  begin
    stringgrid1.Cells[2+i,1]:=tostring(Q[i]);
  end;
  stringgrid1.Cells[n+2,1]:=inttostr(denary);
end;

procedure TForm1.BitBtn1Click(Sender: TObject);
begin
  running:=not running;
  if running=true then bitbtn1.Caption:='stop'else bitbtn1.Caption:='run';
  while running=true do begin
     proses;
     application.ProcessMessages;sleep(500);
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
var i:integer;
begin
  stringgrid1.ColCount:=n+3;
  bitbtn1.Caption:='run';
  stringgrid1.Cells[1,0]:='clock';
  stringgrid1.Cells[1,1]:=tostring(clock);
  for i:=0 to n-1 do  begin
    Q[i]:=false;
    stringgrid1.Cells[2+i,0]:='Q'+inttostr(i);
    stringgrid1.Cells[2+i,1]:=tostring(Q[i]);
  end;
  stringgrid1.Cells[n+2,0]:='Denary';
  stringgrid1.Cells[n+2,1]:=inttostr(denary);
end;

end.

The screenshot.

And the result, :)