Question

Fill-in-the-Blank When a derived class redefines a function in a base class, which version of the function do objects that are defined of the base class call? __________

Short answer

Answer: Objects of the base class call the version of the function in the base class.

Step-by-step solution

Understand the terms involved

In object-oriented programming, classes act as a blueprint to create objects. A derived class is a class that is created by inheriting members (properties or functions) from a base class. When a derived class has a function with the same name (and the same parameters) as one in the base class, this is called function overriding. This allows the derived class to provide a specific implementation for that function.

Answer the question

According to the question, we are asked about objects that are defined of the base class. When a derived class redefines a function in the base class, this will have no impact on objects of the base class. Objects of the base class will always call the version of the function defined in the base class itself. The overridden function in the derived class will only be called for objects of the derived class or its subclasses. So, the answer is "Objects of the base class call the version of the function in the base class."

Key concepts

derived class

In object-oriented programming, a derived class is essentially a specialized version of another class, known as the base class. It is like a child that inherits traits from its parent but can have additional distinctive features of its own.
Derived classes inherit properties and methods from their base classes.

• This inheritance allows for code reusability, making programming more efficient.
• Derived classes can also have additional properties and methods that are specific to their requirements.
• They can override specific methods from the base class to change or enhance behavior.

This powerful feature of object-oriented programming allows a developer to write a class once and use it as a foundation for other classes.

base class

A base class, also known as a parent class, serves as a foundation within object-oriented programming.
It provides a common set of properties and methods that can be used by derived classes.

• Base classes contain the initial functionality, which can be inherited by one or more derived classes.
• They help establish a generic framework that can be extended or customized by derived classes for specific use cases.

When creating a new object from the base class, it will have access to the functions and properties defined within it. This makes the base class an essential part of class hierarchy, providing a starting point for more complex functionalities.

function overriding

Function overriding is a concept where a derived class offers a new version of a method that exists in its base class.
This is useful when a derived class needs to change or add to the functionality of an inherited method.

• To override a function, the derived class must have a method with the same name and parameters as the one in the base class.
• Function overriding ensures the derived class can provide its specific implementation while maintaining the defined interface.

When objects of the derived class call this method, the overridden version is executed. However, objects of the base class will continue to use the base class's version of the function. This is crucial for maintaining the expected behavior for different levels of the class hierarchy.