Smart Pascal : Downto command

SmartPascal
Downto Keyword	Prefixes an decremental for loop target value

1	for Variable := Integer Expression downto Integer Expression do Statement;
2	for Variable := Char Expression downto Char Expression do Statement;
3	for Variable := Enum Expression downto Enum Expression do Statement;

Description

The Downto keyword prefixes the target value Expression in a For loop.

The Downto expression maybe an Integer, Character or Enumeration type.

See the For keyword for full details. The examples illustrate the three expression types.

Related commands

Begin		Keyword that starts a statement block
End		Keyword that terminates statement blocks
For		Starts a loop that executes a finite number of times
To		Prefixes an incremental for loop target value

Example code : Integer for loop

// Full Unit code.
// -----------------------------------------------------------
// You must store this code in a unit called Unit1 with a form
// called Form1 that has an OnCreate event called FormCreate.

unit Unit1;

interface

uses
  SysUtils,
  Forms, Dialogs;

type
  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation
{$R *.dfm} // Include form definitions

procedure TForm1.FormCreate(Sender: TObject);
var
  i : Integer;

begin
  // Loop 5 times
  for i := (10 div 2) Downto 1 do
    ShowMessage('i = '+IntToStr(i));
end;

end.

Hide full unit code

   i = 5
   i = 4
   i = 3
   i = 2
   i = 1

Example code : Character for loop

var
  c : char;
begin
  // Loop 5 times
  for c := 'E' Downto 'A' do
    ShowMessage('c = '+c);
end;

Show full unit code

   c = E
   c = D
   c = C
   c = B
   c = A

Example code : Enumeration for loop

var
  suit : (Hearts, Clubs, Diamonds, Spades);
begin
  // Loop 3 times
  for suit := Diamonds Downto Hearts do
    ShowMessage('Suit = '+IntToStr(Ord(suit)));
end;

Show full unit code

   Suit = 2
   Suit = 1
   Suit = 0