Exploring the Fundamentals of object-oriented programming with Java

(Third Part — Inheritance)

Today, we will continue exploring the fundamentals of object-oriented programming with Java. In the previous parts, we covered the concept of Encapsulation, including what it is and the role that access modifiers play in achieving encapsulation. However, we covered as well that access modifiers are not the only way to ensure encapsulation.

Today, we will shift our focus to another important concept in object-oriented programming, which is inheritance. We will explore the meaning of inheritance and its importance.

The article will be structured as follows:

Inheritance.

“Is-a” relationship.

Benefits of inheritance.

Inheritance

Inheritance is one of the fundamental concepts of object-oriented programming (OOP). It allows classes to inherit properties and behaviors from other classes, creating a hierarchy of classes.

Now that we understand objects in object-oriented programming (OOP) represent entities from the real world in a development context, let us delve into the concept of inheritance. Inheritance is a powerful tool that addresses the challenge of implementing diverse animals in a zoo application.

In this scenario, animals in the zoo exhibit differences — some can fly, some can swim, and they may have different numbers of legs. Creating separate objects for each animal would be cumbersome and result in repetitive code. This is where inheritance comes in.

By utilizing inheritance, we can create subclasses (derived or child classes) that inherit properties, methods, and behaviors from a superclass (base or parent class). The subclass is a specialized version of the superclass.

In our example, we can have a superclass that encompasses common attributes such as Name, Age, Gender, Weight, Color, and others. Each subclass representing a specific animal will inherit these common attributes and may also have their own unique attributes.

“Is-a” relationship

In Java, the “is-a” relationship is a fundamental concept in object-oriented programming and is realized through inheritance. It establishes a relationship between classes, where one class is considered a specific type of another class.

The “is-a” relationship is often described using the phrase “Class A is a Class B.” This means that Class A inherits from Class B and shares its attributes, methods, and behaviors. Class A is considered a subtype or subclass of Class B.

Let’s consider an example: a dog is an animal. In this situation, we can establish an inheritance relationship between the dog and the animal. However, we cannot say that a car is an animal. In such cases, inheritance cannot be applied.

Benefits of inheritance

Inheritance offers several benefits in object-oriented programming:

Code Reusability, Inheritance allows subclasses to inherit properties, methods, and behaviors from a superclass, promoting code reuse. This saves time and effort by eliminating the need to rewrite or duplicate code.

Code Organization, Inheritance facilitates the organization of classes into a hierarchical structure based on their common attributes and behaviors. This helps in managing and maintaining code by providing a clear and structured design.

Conceptual Modeling: Inheritance helps in representing real-world relationships and concepts in software systems. It allows for the modeling of “is-a” relationships, where subclasses represent more specific types or variations of the superclass.

Overall, inheritance enhances the flexibility, maintainability, and scalability of code by providing a mechanism for code reuse, organization, and extensibility. It is a fundamental concept in object-oriented programming that promotes efficient and effective software development.