Question

A base class pointer needs a(n) _________ to be assigned to a derived class pointer.

Short answer

Answer: Downcast

Step-by-step solution

Identify the missing word

In the context of the exercise, when a base class pointer needs a(n) _________ to be assigned to a derived class pointer, we are looking for the term "downcast".

Understand the concept of inheritance

Inheritance is a feature of object-oriented programming that allows a class to inherit properties and methods from another class. In this relationship, the class that inherits from another class is called the derived class, and the class that is inherited from is called the base class.

Assign a base class pointer to a derived class pointer

To assign a base class pointer to a derived class pointer, we need to use a technique called downcasting. It will allow us to access the derived class object using the base class pointer. Downcasting can be done using either static_cast or dynamic_cast, depending on the situation.

Example: Inheritance and downcasting using static_cast

Let's assume we have a base class "Animal" and two derived classes "Dog" and "Cat". ``` class Animal { public: virtual void make_sound() = 0; }; class Dog : public Animal { public: void make_sound() override { cout << "Woof" << endl; } }; class Cat : public Animal { public: void make_sound() override { cout << "Meow" << endl; } }; ```

Assigning a derived class pointer to a base class pointer using downcasting

To assign a base class pointer to a derived class object, we can use downcasting. Let's create an object of the derived class "Dog" and assign it to a base class "Animal" pointer using static_cast. ```cpp int main() { Dog dog1; // Creating a Dog object Animal* animalPtr = &dog1 // Assigning the dog object to a base class pointer // Downcasting base class pointer to a derived class pointer Dog* dogPtr = static_cast(animalPtr); dogPtr->make_sound(); // Accessing derived class function using downcasted pointer } ``` This example demonstrates how downcasting allows us to assign a base class pointer to a derived class object.