for Robot Artificial Inteligence

15. Polymorphism-Virtual-Functions-Abstracts-Classes

15 Sep 2019 | C++

Virtual

Exercise

Main.cpp

#include <iostream>
#include "farm.h"

using namespace std;
/* polymorphism, virtual functions, abstract class */
void voiceOfAnimal(Animal *);
void voiceOfAnimal(Animal &);
int main()
{

    Dog dog;
    Cat cat;
    Cow cow;
/*
    cout << animal.getVoice() << endl;
    cout << dog.getVoice() << endl;
    cout << cat.getVoice() << endl;
    cout << cow.getVoice() << endl;
    */
    voiceOfAnimal(&cow); // why we use & because it is for class usually. so it took as reference



    return 0;
}
void voiceOfAnimal(Animal *p)
{
    cout << p->getVoice() << endl;
}
void voiceOfAnimal(Animal &p)
{
    cout << p.getVoice() << endl;
}

farm.h

#ifndef FARM_H_INCLUDED
#define FARM_H_INCLUDED
#include <iostream>

using namespace std;

class Animal
{
        protected:
            string voice;
        public:
            Animal();
            ~Animal();
            virtual string getVoice() = 0; // 가상함수로 선언하여 유도 클래스 Getvoice를 쓸 수 있게 함
};
class Dog : public Animal
{
            string sign;
        public:
            Dog();
            ~Dog();
            string getVoice() { return voice + " " + sign; }
};
class Cat : public Animal
{
            string sign;
        public:
            Cat();
            ~Cat();
            string getVoice() { return voice  + " " +  sign; }
};
class Cow : public Animal
{
            string sign;
        public:
            Cow();
            ~Cow();
            string getVoice() { return voice  + " " +  sign; }
};

#endif // FARM_H_INCLUDED

farm.cpp

#include "farm.h"


Animal::~Animal()
{

}
Dog::Dog()
{
    sign = "D";
    voice = "hau";
}
Dog::~Dog()
{

}
Cat::Cat()
{
    sign = "C";
    voice = "meow";
}
Cat::~Cat()
{

}
Cow::Cow()
{
    sign = "CO";
    voice = "moooo";
}
Cow::~Cow()
{

}

Virtual destructor

  • First of all, it call Dog Class as sub-class within Dynamic
  • then it call Animal Class as Base-Class within pointer. because of it instance called by dynamic

main.cpp

#include <iostream>
#include "farm.h"

using namespace std;
/* virtual destructor */
void voiceOfAnimal(Animal *);
void voiceOfAnimal(Animal &);
int main()
{
/*
    Dog dog;
    Cat cat;
    Cow cow;

    cout << animal.getVoice() << endl;
    cout << dog.getVoice() << endl;
    cout << cat.getVoice() << endl;
    cout << cow.getVoice() << endl;

    voiceOfAnimal(&cow);

*/
    Animal *dog = new Dog;

    delete dog;
    return 0;
}
void voiceOfAnimal(Animal *p)
{
    cout << p->getVoice() << endl;
}
void voiceOfAnimal(Animal &p)
{
    cout << p.getVoice() << endl;
}

farm.h

#ifndef FARM_H_INCLUDED
#define FARM_H_INCLUDED
#include <iostream>

using namespace std;

class Animal
{
        protected:
            string voice;
        public:
            Animal();
            virtual ~Animal();
            virtual string getVoice() = 0;
};
class Dog : public Animal
{
            string sign;
        public:
            Dog();
            ~Dog();
            string getVoice() { return voice + " " + sign; }
};
class Cat : public Animal
{
            string sign;
        public:
            Cat();
            ~Cat();
            string getVoice() { return voice  + " " +  sign; }
};
class Cow : public Animal
{
            string sign;
        public:
            Cow();
            ~Cow();
            string getVoice() { return voice  + " " +  sign; }
};

#endif // FARM_H_INCLUDED

farm.cpp

#include "farm.h"

Animal::Animal()
{

}
Animal::~Animal()
{
    cout << "im from the base class " << endl;
}
Dog::Dog()
{
    sign = "D";
    voice = "hau";
}
Dog::~Dog()
{
    cout << "im from the sub-class " << endl;
}
Cat::Cat()
{
    sign = "C";
    voice = "meow";
}
Cat::~Cat()
{
    cout << "im from the sub-class " << endl;
}
Cow::Cow()
{
    sign = "CO";
    voice = "moooo";
}
Cow::~Cow()
{
    cout << "im from the sub-class " << endl;
}

Related Posts

Comments