C++课后习题 17. 教材习题8

• • 原题题目
  • 代码实现
  • 提交结果

#include  
using  namespace  std;

class Mammal {
 public:
  virtual void speak() const = 0;
};

class Dog : public Mammal {
 public:
  virtual void speak() const override {
    cout << "Dog is speaking!" << endl;
  }
};

int  main()
{
  Dog dog;
  Mammal *p;

  dog.speak();
  p=&dog;
  p->speak();
}