/* An example of abstraction, the following concepts are shown: - inheritance - polymorphism - virtual function - pure virtual function - heterogeneous container sorry for the errors in my language, i do not speak english. Please leave a comment if you have something to add ! */ #include #include #include // Creation of our abstract class Animal class Animal { public: Animal(std::string const& name, int age = 0) : m_name(name), m_age(age){} virtual ~Animal(){} // Notice that the destructor of a class that will be inherited should be always virtual virtual std::string sound() const = 0; // a pure virtual function virtual void sayHello() { std::cout << "My name is " << m_name << " and I'm " << m_age << " years old" << std::endl; }; // a virtual function protected: std::string m_name; int m_age; }; // a cat is an animal so the class Cat inherits from the class Animal class Cat : public Animal { public: Cat(std::string const& name, int age = 0) : Animal(name, age) {} ~Cat() {}; std::string sound() const { return std::string("Meow"); } // we override the pure virtual function void sayHello() { std::cout << "Hello I'm a cat" << std::endl; Animal::sayHello(); } void askHug() { std::cout << "purr" << std::endl; } protected: }; // an other derived class is Dog class Dog : public Animal { public: Dog(std::string const& name, int age = 0) : Animal(name, age) {} ~Dog() {}; std::string sound() const { return std::string("Woof"); } void sayHello() { std::cout << "Hello I'm a dog" << std::endl; Animal::sayHello(); } void goGetABone() { std::cout << "I want my bone !" << std::endl; } protected: }; int main(int argc, char*argv[]) { // BE AWARE this code does NOT handle bad allocation of memories and it might be memory leak. std::vector animals; // a heterogeneous container animals.push_back(new Cat("Cat1", 5)); animals.push_back(new Dog("Dog1", 7)); for (auto animal : animals) { animal->sayHello(); std::cout << animal->sound() << std::endl << std::endl; } for (int i(0); i < animals.size(); i++) { delete animals[i]; // don’t forget to release the memory } return 0; }