C++의 다형성은 유연하고 확장 가능한 코드를 만드는 데 어떻게 도움이 됩니까?

class Base {
public:
    virtual void display() {
        cout << "Base class display function" << endl;
    }
};

class Derived : public Base {
public:
    virtual void display() override {
        cout << "Derived class display function" << endl;
    }
};

class Base {
public:
    virtual void display() {
        cout << "Base class display function" << endl;
    }
};

class Derived : public Base {
public:
    virtual void display() override {
        cout << "Derived class display function" << endl;
    }
};

int main() {
    Base* ptr = new Derived(); // 指向 Derived 对象的 Base 类指针
    ptr->display(); // 调用 Derived 类中的 display 函数
}

class Shape {
public:
    virtual float area() = 0; // 纯虚函数
};

class Circle : public Shape {
public:
    Circle(float radius) : mRadius(radius) {}
    float area() override {
        return 3.14 * mRadius * mRadius;
    }

private:
    float mRadius;
};

class Rectangle : public Shape {
public:
    Rectangle(float width, float height) : mWidth(width), mHeight(height) {}
    float area() override {
        return mWidth * mHeight;
    }

private:
    float mWidth;
    float mHeight;
};

int main() {
    Shape* shapes[] = {new Circle(5), new Rectangle(10, 5)};

    for (Shape* shape : shapes) {
        cout << "Area: " << shape->area() << endl;
    }

    return 0;
}