Question

If every C1 class object can be used as a C2 class object, the relationship between the two classes should be implemented using _________.

Short answer

Answer: Inheritance

Step-by-step solution

Identifying the concept

The concept we need to apply here is 'inheritance' which allows an object of one class to be used as an object of another class.

Fill in the blank

Since the relationship between the two classes should be implemented using inheritance, the sentence would be: If every C1 class object can be used as a C2 class object, the relationship between the two classes should be implemented using 'inheritance.'

Key concepts

Object-Oriented Programming

Object-Oriented Programming (OOP) is a paradigm that organizes software design around data, or objects, rather than functions and logic. An object can be conceived as a self-contained unit with a distinct role or responsibility within a program.

In OOP, a program is typically made up of multiple objects that interact with each other to perform the program's functions. This design approach helps to make software more modular, flexible, and easier to understand. OOP is built upon several key principles, such as encapsulation, abstraction, polymorphism, and inheritance. Each of these plays a vital role in contributing to the robust nature of an OOP-designed system. For instance, encapsulation enables an object to hide its data, providing a public interface for interaction while preventing external interference with its internal workings.

C++ Class Relationship

In C++, class relationships govern how classes interact and work with one another. Understanding these relationships is crucial for designing an effective object-oriented system. There are various types of class relationships, but the most fundamental are association, aggregation, composition, and inheritance.

Association represents a “uses-a” relationship, where one class makes use of the functionality of another. Aggregation and composition both express a “has-a” relationship, but with different degrees of ownership and lifespan implications. Aggregation implies a weaker association where entities can exist independently. On the other hand, composition suggests a strong relationship where a part cannot exist without the whole.

Inheritance in C++

Inheritance, specifically, is a 'is-a' relationship that enables one class (subclass or derived class) to inherit the attributes and behaviors of another (superclass or base class), often leading to code reuse and a simpler hierarchy.

Inheritance Hierarchy

An inheritance hierarchy is a structure in C++ that illustrates the relationships between base classes and derived classes. In such a hierarchy, derived classes extend the functionality of their base classes, adding new attributes or modifying existing behaviors.

Classes higher up in the hierarchy are more general, while those at the lower levels are more specialized. This hierarchy enables a clear structure by showing how classes are connected through inheritance. It allows the implementation of polymorphism, where a derived class object can be treated as an object of its base class, enabling the use of generic interfaces for diverse object types.

Moreover, a well-designed inheritance hierarchy should follow the 'Liskov Substitution Principle' which essentially states that objects of a superclass should be replaceable with objects of a subclass without affecting the correctness of the program. This principle underlines the given exercise, implying how a C1 object's usability in place of a C2 object advocates proper adherence to an inheritance hierarchy.