Base and Derived CPP Classes

main.cpp

#include <iostream>

class Base {
protected:
	int value; // Derived class will have access.
public:
	Base(int value) : value{value} {
		std::cout << "Base Constructor\n";
	}

	virtual ~Base() {} // Sets up the Base as having polymorphic relationship with Derived

	int getValue() const {
		return value;
	}

	std::string getName() const {
		return "Base";
	}
};

class Derived : public Base {
	double age;
public:
	Derived(int value, double age) : Base{ value }, age{ age } // equivalent of super(value) 
	{
		std::cout << "Derived Constructor\n";
	}

	std::string getName() const {
		return "Derived";
	}

	int getDoubleValue() const {
		return value * 2;
	}

	double getAge() const {
		return age;
	}
};

int main()
{
	Base myBase{ 25 };
	Derived myDerived{ 33, 25.3 };

	std::cout << "## ACCESSING Base myBase\n";
	std::cout << myBase.getName() << " : " << myBase.getValue() << "\n";

	std::cout << "## ACCESSING Derived myDerived\n";
	std::cout << myDerived.getName() << " : " << myDerived.getValue();
	std::cout << " : " << myDerived.getAge() << " : " << myDerived.getDoubleValue() << "\n";

	Derived& derivedRef{ myDerived };
	
	std::cout << "## ACCESSING Derived& derivedRef{myDerived}\n";
	std::cout << derivedRef.getName() << " : " << derivedRef.getValue();
	std::cout << " : " << derivedRef.getAge() << " : " << derivedRef.getDoubleValue() << "\n";

	Derived* derivedPointer{ &myDerived };

	std::cout << "## ACCESSING Derived* derivedPointer{&myDerived}\n";
	std::cout << derivedPointer->getName() << " : " << derivedPointer->getValue();
	std::cout << " : " << derivedPointer->getAge() << " : " << derivedPointer->getDoubleValue() << "\n";

	Base& baseRefToBase{ myBase };
	Base& baseRefToDerived{ myDerived };
	Base* basePointerToDerived{ &myDerived };

	std::cout << "## ACCESSING Base& baseRefToBase{ myBase }\n";
	std::cout << baseRefToBase.getName() << " : " << baseRefToBase.getValue() << "\n";
	
	std::cout << "## ACCESSING Base& baseRefToDerived{ myDerived }\n";
	std::cout << baseRefToDerived.getName() << " : But actually I'm a: "
	          << dynamic_cast<Derived&>(baseRefToDerived).getName() 
	          << " : " << dynamic_cast<Derived&>(baseRefToDerived).getAge() << "\n";

	std::cout << "## ACCESSING Base* basePointerToDerived{ &myDerived }\n";
	std::cout << basePointerToDerived->getName() << " : But actually I'm a: "
	          << dynamic_cast<Derived*>(basePointerToDerived)->getName() 
	          << " : " << dynamic_cast<Derived*>(basePointerToDerived)->getAge() << "\n";
}