C++教程:C++虚函数与虚析构函数

{
   cout <<"Animal consturctor is running..." <<endl;
   weight=w;
   age=a;
}
Animal::~Animal()
{
   cout <<"Animal destructor is running..." <<endl;
}
//cat.h
#include "animal.h"
class Cat:public Animal
{
   public:
   Cat(int w=0,int a=0);
   ~Cat();
};
Cat::Cat(int w,int a):Animal(w,a)
{
      cout <<"Cat constructor is running..." <<endl;