C + + polymorphic

Polymorphism (polymorphic)

Upcast:take an object of the derived class as an object of the base one.

-ellipse can treated as a Shape

Dynamic binding (dynamically bound)

-binding:which function to be called

-static Binding:call The function as the code (static binding, compiled when already determined,)

-dynamic Binding:call The function of the object (dynamic binding, which determines which function k is called by the runtime based on the object pointed to by the pointer, is related to virtual render ())

classxypos{};//Xy,pointclassshape{ Public: Shape (); Virtual~shape ();//virtual function,a subclass is related to a function of the parent class    Virtual voidrender (); voidMoveConstXypos &); Virtual voidresize ();protected: Xypos Center;};classEllipse: Publicshape{ Public: Ellipse (floatMajfloatMinr); Virtual voidRender ();//Would define ownprotected:    floatMajor_axis, Minor_axis;};classCircle: Publicellipse{ Public: Circle (floatradius): Ellipse (radius, radius) {}; Virtual voidrender ();};voidRender (shape*p) {P->render ();//invokes the correct render function according to the given shape;}voidfunc () {Ellipse ell (Ten, -);    Ell.render (); Circle Circ ( +);    Circ.render (); Render (&ell); Render (&circ);}

C + + polymorphic