Классы и жизненный цикл объектов

// Исключение возникает во втором создаваемом объекте.
program ConstructorExceptionTrace;
{$APPTYPE CONSOLE}
uses System.SysUtils;

type
  TProbe = class
  public
    class var Alive: Integer;
    constructor Create(AFail: Boolean);
    destructor Destroy; override;
  end;

  TPair = class
  private
    FFirst: TProbe;
    FSecond: TProbe;
  public
    constructor Create;
    destructor Destroy; override;
  end;

constructor TProbe.Create(AFail: Boolean);
begin
  inherited Create;
  Inc(Alive);
  if AFail then
    raise Exception.Create('Сбой');
end;

destructor TProbe.Destroy;
begin
  Dec(Alive);
  inherited;
end;

constructor TPair.Create;
begin
  inherited Create;
  FFirst := TProbe.Create(False);
  FSecond := TProbe.Create(True);
end;

destructor TPair.Destroy;
begin
  FSecond.Free;
  FFirst.Free;
  inherited;
end;

begin
  try
    TPair.Create;
  except
    on E: Exception do
      Writeln(TProbe.Alive);
  end;
end.

// Определите реальную гарантию в Ownership.
program Ownership;
{$APPTYPE CONSOLE}
uses System.Classes;
procedure LoadNames(const FileName: string);
var
  Names: TStringList;
begin
  Names := TStringList.Create;
  try
    Names.LoadFromFile(FileName);
    Writeln(Names.Count);
  finally
    Names.Free;
  end;
end;
begin end.

// Отделите правило языка от удачного запуска FreeNil.
program FreeNil;
{$APPTYPE CONSOLE}
uses System.SysUtils;
var
  Obj: TObject;
begin
  Obj := nil;
  Obj.Free;
  Obj := TObject.Create;
  try
    Writeln(Obj.ClassName);
  finally
    FreeAndNil(Obj);
  end;
end.

// Определите реальную гарантию в DestructorOrder.
program DestructorOrder;
{$APPTYPE CONSOLE}
type
  TBase = class
    destructor Destroy; override;
  end;
  TChild = class(TBase)
  private
    FData: TObject;
  public
    destructor Destroy; override;
  end;
destructor TBase.Destroy;
begin
  Writeln('base');
  inherited;
end;
destructor TChild.Destroy;
begin
  FData.Free;
  Writeln('child');
  inherited;
end;
begin end.