SmartPascal
$Hints
Compiler Directive
Determines whether Delphi shows compilation hints
1   {$Hints Off}
2   {$Hints On}
Description
The $Hints compiler directive determines whether Delphi shows compilation hints or not.
 
Hints are very useful for pointing out potential or real code problems. You should always have hints on, and ideally always change your code so that there are no compilation hints. It is all too easy to see hints as irritations, but they are there for a real purpose.
Notes
The default value is $Hints On

$Hints should be set only once in your code.
Related commands
$Warnings Determines whether Delphi shows compilation warnings
 
Example code : Give hints for failing to use a variable, and to use an assigned value
var
  i,j : Integer;
begin
  // Set hints on
  {$Hints On}

  // Set i to a known value
  i := 234;
end;
Show full unit code
   Hints displayed :
  
   [Hint] Unit1.pas(40): Value assigned to 'i' never used
   [Hint] Unit1.pas(34): Variable 'j' is declared but never used in 'TForm1.FormCreate'
 
Example code : No hints for failing to use a variable, and to use an assigned value
// 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
  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,j : Integer;
begin
  // Set hints off
  {$Hints Off}

  // Set i to a known value
  i := 234;
end;
 
end.
Hide full unit code
   Code gives no hints