C++ pointer to base class

In C++, a pointer to a base class can be used to point to an object of a derived class. This allows for polymorphism, where a function or method can be called on the pointer, and the appropriate method from the derived class will be executed.

Here are the steps involved in using a pointer to a base class:

  1. Declare a base class: First, you need to declare a base class that will serve as the common interface for all derived classes. This class should define any common attributes or methods that will be shared by all derived classes.

  2. Declare a derived class: Next, declare a derived class that inherits from the base class. The derived class will inherit the attributes and methods of the base class and can also add its own unique attributes and methods.

  3. Create objects of derived classes: Create objects of the derived classes using the 'new' keyword. Each object will have its own memory space and will be initialized with the attributes and methods of both the base and derived classes.

  4. Create a pointer to the base class: Declare a pointer to the base class using the base class type. This pointer can be used to point to objects of both the base and derived classes.

  5. Assign the derived class object to the base class pointer: Assign the address of a derived class object to the base class pointer using the assignment operator '='. This allows the pointer to point to the derived class object.

  6. Access methods using the pointer: You can now use the pointer to call methods that are defined in the base class. If the derived class overrides any of these methods, the overridden method in the derived class will be executed instead.

  7. Delete objects and free memory: After you have finished using the objects and the pointer, make sure to delete the objects using the 'delete' keyword to free the memory allocated for them.

It's important to note that using a pointer to a base class allows for more flexibility and polymorphism in your code. You can have a collection of objects of different derived classes and access them through a single pointer to the base class, which can make your code more modular and reusable.