Hello Jetto Net followers!

Welcome to our Java Object-Oriented Programming (OOP) series. In our previous article, we explored methods and access modifiers that define the behaviors of objects. In this article, we will dive into "inheritance," one of the most powerful features of OOP.

What is Inheritance?

Inheritance is when a class (subclass or derived class) inherits properties and behaviors from another class (superclass or base class). This allows us to avoid rewriting existing class features when creating new classes. The properties and behaviors inherited from the superclass can be directly used in the subclass or redefined by the subclass. It might be challenging to grasp theoretically, so let's go through an example:

Suppose we are developing an automation system to store various information about employees in a company. We could define a class named Employee in this automation to handle our operations. If we want to provide additional rights to General Managers, who should have more privileges than the Employee class, we need to use the inheritance feature.

Using Inheritance in Java

In Java, inheritance is implemented using the extends keyword. The superclass is specified with the extends keyword in the subclass. This allows the subclass to inherit from the superclass and access all its properties.

public class Car { // Superclass (base class)
   // (Contains properties like brand, model, year, color and behaviors like accelerate(), decelerate())
}
public class ElectricCar extends Car { // Subclass (derived class)
   // (Contains additional properties like batteryCapacity and behaviors like charge())
   // (Also has access to all properties and behaviors of the Car class)
}

In the example above, the ElectricCar class extends the Car class. This means the ElectricCar class inherits all the properties and behaviors of the Car class. Additionally, the ElectricCar class can define its own properties (batteryCapacity) and behaviors (charge()).

Types of Inheritance

• Single Inheritance: A subclass inherits from only one superclass. Java only supports single inheritance.
• Multiple Inheritance: A subclass inherits from more than one superclass. Java does not directly support multiple inheritance, but similar functionality can be achieved through interfaces.
• Multilevel Inheritance: A subclass inherits from another subclass. For example, the ElectricCar class inherits from the Car class, while the Car class inherits from the MotorVehicles class, creating an inheritance chain.
• Hierarchical Inheritance: Multiple subclasses inherit from a single superclass. For example, both the Car and Motorcycle classes can inherit from the MotorVehicles class, forming hierarchical inheritance.

Benefits of Inheritance

• Code Reusability: With inheritance, we can reuse the properties and behaviors of existing classes, preventing code duplication in our program. This accelerates software development and reduces the likelihood of errors.
• Extensibility: Inheritance allows us to add new features and behaviors without modifying the existing class. This makes our code more flexible and adaptable.
• Readability: Inheritance displays the relationships between classes in a hierarchical structure, making the code more readable.

Conclusion

Inheritance is one of the most important and powerful tools in Java's object-oriented programming. By using inheritance, we can make our code more organized, reusable, and flexible. In our next article, we will continue to explore other important concepts of OOP. Stay tuned!

You can share your questions or thoughts in the comments section. Happy coding!