Try It Yourself - SyntaxStudy Editor

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#include <iostream>
#include <string>

// Base class
class Animal {
public:
    explicit Animal(const std::string& name, int age)
        : name_(name), age_(age) {
        std::cout << "Animal constructed: " << name_ << "
";
    }

// Virtual destructor — essential for polymorphic use
    virtual ~Animal() {
        std::cout << "Animal destroyed: " << name_ << "
";
    }

std::string name() const { return name_; }
    int         age()  const { return age_;  }

virtual void speak() const {
        std::cout << name_ << " makes a sound.
";
    }

protected:
    std::string name_;
    int         age_;
};

// Derived class
class Dog : public Animal {
public:
    Dog(const std::string& name, int age, const std::string& breed)
        : Animal(name, age)   // call base constructor explicitly
        , breed_(breed)
    {
        std::cout << "Dog constructed: " << breed_ << "
";
    }

~Dog() override {
        std::cout << "Dog destroyed: " << name_ << "
";
    }

void speak() const override {
        std::cout << name_ << " barks!
";
    }

std::string breed() const { return breed_; }

private:
    std::string breed_;
};

int main() {
    Animal* a = new Dog("Rex", 3, "Labrador");
    a->speak();
    std::cout << "Breed: " << static_cast<Dog*>(a)->breed() << "
";
    delete a;   // calls Dog::~Dog then Animal::~Animal (virtual)
    return 0;
}