Exploring the Fundamentals of object-oriented programming with Java

(Fourth Part — Polymorphism)

Today marks the Fourth part of our exploration into the fundamentals of object-oriented programming with Java. The image illustrates the flexibility and interchangeability of objects in polymorphism, as the music player can interact with each instrument using the same interface, allowing for dynamic and versatile usage of objects in the program.

We will begin by discussing polymorphism and exploring its concept. Then, we will dive into the topic of abstraction. Our article will be structured as follows:

Polymorphism

Compile-time Polymorphism (Method Overloading)

Runtime Polymorphism (Method Overriding)

Polymorphism

Polymorphism is another fundamental concept in object-oriented programming (OOP) that allows objects of several types to be treated as objects of a common superclass. It supplies a way to perform a single action in diverse ways based on the object’s specific type or class.

There are two main types of polymorphism: compile-time polymorphism and runtime polymorphism.

Compile-time Polymorphism (Method Overloading)

Compile-time polymorphism, also known as method overloading, is a feature in Java that allows multiple methods with the same name but different parameters to exist within a class. Each overloaded method performs a different operation or accepts several types of arguments, supplying flexibility and convenience in method invocation.

To make it easier to understand, let us consider a calculator project where we have a function for addition. Sometimes we need to add two values, other times three, and sometimes four. We would have to create separate functions with different names and argument types to handle each case. This is where method overloading becomes valuable. It allows us to define multiple functions with the same name but different arguments. So, if we have an “add” function with two arguments, it will behave accordingly, and if we have another “add” function with three arguments, it will behave differently. Method overloading provides flexibility and allows us to handle different scenarios with a single function name.

Now, let us see how method overloading benefits us:

1. Convenience: By overloading the add method, we can perform addition with several types of data without needing to remember or use different method names. We can add two integers, two doubles, or even three integers using the same method name add, making it more intuitive and convenient for developers.
2. Code Readability: Method overloading improves code readability by allowing us to express our intentions more clearly. When we invoke the add method, we do not need to rely on additional method names like addInt, addDouble, or addThreeIntegers. Instead, we use the same method name add and let the compiler decide the right method based on the arguments we provide.
3. Flexibility: Method overloading supplies flexibility in handling different scenarios. For example, we can perform addition of two integers, addition of two doubles, or addition of three integers by using the same method name add. This allows us to write cleaner code by reusing method names and logic, reducing the need for duplicating code.

By using method overloading, we can write more concise and expressive code that is easier to understand and maintain. It promotes code reusability, enhances readability, and supplies flexibility in handling several types of data and scenarios.

Runtime Polymorphism (Method Overriding)

Runtime polymorphism, also known as method overriding, is a fundamental concept in object-oriented programming that allows a subclass to provide its own implementation of a method defined in its superclass. This enables objects of different classes to respond to the same method call in different ways, based on their specific implementations.

We have a base class called Animal, which has a method called makeSound. Two subclasses, Dog and Cat, extend the Animal class and override the makeSound method. By default, if we don’t override the method, both Dog and Cat will inherit the same sound implementation. However, this can be problematic because dogs and cats make different sounds. That’s where method overriding comes in. It allows us to modify or overwrite the logic inside the makeSound method for each subclass. This way, each dog and cat can have its own unique implementation of the makeSound method.

Now, let us see how method overloading benefits us:

1. Code reusability: Method overriding allows us to define a common interface or behavior in the base class and provide specific implementations in the derived classes. This promotes code reuse, as we can leverage the existing functionality while adding specific behaviors as needed.
2. Flexibility and extensibility: Method overriding enables us to create more flexible and extensible code. We can define generic methods in the base class and override them in the derived classes to tailor the behavior to specific requirements. This flexibility allows for easy modifications and additions to the code without affecting the existing functionality.
3. Improved code organization: Method overriding promotes better code organization by grouping related behaviors in separate classes. It allows us to define specific behaviors in the appropriate derived classes, making the code more organized, modular, and easier to understand and maintain.
4. Enhancing readability and maintainability: Method overriding enhances the readability and maintainability of the code. It makes the code more intuitive and self-explanatory by providing specific implementations for different objects. This helps other developers understand the code more easily and makes it easier to locate and modify specific behaviors when needed.

Overall, runtime polymorphism (method overriding) enhances code flexibility, reusability, and maintainability, and enables the creation of more robust and adaptable object-oriented systems.

Polymorphism is a powerful concept in OOP as it promotes code reusability, flexibility, and extensibility. It allows for more generic and flexible code design by treating objects based on their common interface or superclass, rather than their specific type.