Initial data commit

Task/Polymorphism/Delphi/polymorphism-1.delphi

@@ -0,0 +1,107 @@
+type
+  { TPoint }
+
+  TMyPoint = class
+  private
+    FX: Integer;
+    FY: Integer;
+  public
+    constructor Create; overload;
+    constructor Create(X0: Integer; Y0: Integer); overload;
+    constructor Create(MyPoint: TMyPoint); overload;
+    destructor Destroy; override;
+
+    procedure Print; virtual;
+
+    property X: Integer read FX write FX;
+    property Y: Integer read FY write FY;
+  end;
+
+  { TCircle }
+
+  TCircle = class(TMyPoint)
+  private
+    FR: Integer;
+  public
+    constructor Create(X0: Integer; Y0: Integer; R0: Integer); overload;
+    constructor Create(MyPoint: TMyPoint; R0: Integer); overload;
+    constructor Create(Circle: TCircle); overload;
+    destructor Destroy; override;
+
+    procedure Print; override;
+
+    property R: Integer read FR write FR;
+  end;
+
+implementation
+
+uses Dialogs;
+
+{ TCircle }
+
+constructor TCircle.Create(X0: Integer; Y0: Integer; R0: Integer);
+begin
+  inherited Create(X0, Y0);
+  FR := R0;
+end;
+
+constructor TCircle.Create(MyPoint: TMyPoint; R0: Integer);
+begin
+  inherited Create(MyPoint);
+  FR := R0;
+end;
+
+constructor TCircle.Create(Circle: TCircle);
+begin
+  Create;
+  if not(Circle = Self) then
+  begin
+    FX := Circle.X;
+    FY := Circle.Y;
+    FR := Circle.R;
+  end;
+end;
+
+destructor TCircle.Destroy;
+begin
+  inherited Destroy;
+end;
+
+procedure TCircle.Print;
+begin
+   ShowMessage('Circle');
+end;
+
+{ TMyPoint }
+
+constructor TMyPoint.Create;
+begin
+  inherited Create;
+end;
+
+constructor TMyPoint.Create(X0: Integer; Y0: Integer);
+begin
+  Create;
+  FX := X0;
+  FY := Y0;
+end;
+
+constructor TMyPoint.Create(MyPoint: TMyPoint);
+begin
+  Create;
+  if not(MyPoint = Self) then
+  begin
+    FX := MyPoint.X;
+    FY := MyPoint.Y;
+  end;
+end;
+
+destructor TMyPoint.Destroy;
+begin
+  inherited Destroy;
+end;
+
+procedure TMyPoint.Print;
+begin
+  ShowMessage('MyPoint');
+end;

Task/Polymorphism/Delphi/polymorphism-2.delphi

@@ -0,0 +1,17 @@
+var
+  MyPoint: TMyPoint;
+  Circle: TCircle;
+begin
+  MyPoint := TMyPoint.Create;
+  try
+    MyPoint.Print;
+    Circle := TCircle.Create;
+    try
+      Circle.Print;
+    finally
+      FreeAndNil(Circle);
+    end;
+  finally
+    FreeAndNil(MyPoint);
+  end;
+end;