1. Introduction to polymorphism
Polymorphism is a concept in Object-Oriented Programming (OOP) that allows objects to exist in multiple forms. This idea can be a bit challenging for programmers to grasp, so let’s break it down with an example.
2. Demonstrating polymorphism
What Is Polymorphism
Consider an abstract class called Car, which has an abstract method called drive(). Different car classes, such as Toyota, Tesla, and Lamborghini, inherit from this Car class. Each model has its own unique implementation of the drive() method. For instance, a Toyota drives differently than a Tesla, and both differ from a Lamborghini. To make our code function properly, we need to implement these distinct methods in each class.
3. Overriding methods
In Java, polymorphism is facilitated through the @Override annotation, which allows us to customize inherited methods. For our Toyota class, we can override the drive() method by using the @Override annotation, which indicates that we are providing a custom implementation. The drive() method in the Toyota class matches the version from the Car class, allowing us to define how a Toyota specifically drives. The same principle applies to the Tesla and Lamborghini classes, each implementing their unique versions of the drive method.
4. Overriding interface methods
Methods can be overridden from both classes and interfaces. For instance, we can implement an ElectricCar interface in the Tesla class, which includes an abstract charge() method, allowing for a custom implementation of charge().
5. Overloading methods
In addition to overriding, overloading is also a concept in OOP. Overloading allows us to create multiple methods with the same name but different implementations. For example, the Toyota class can use the drive() method without parameters. We could also create another drive() method that accepts a topSpeed parameter.
6. Overloading the constructor
Constructor overloading is a common practice as well. Suppose we create a new Honda class with the properties color, model, and licensePlate. The first constructor can take color and model as parameters, while a second constructor might include color, model, and licensePlate. We can then instantiate two Honda objects: one using the first constructor (hondaOne) and the other using the second constructor (hondaTwo), which includes all three properties.
7. Let's practice!
In summary, polymorphism may seem complex at first, but it fundamentally refers to the ability of an object to take on multiple forms. By understanding and implementing both method overriding and overloading, you can effectively utilize polymorphism in your code. It’s now time for you to begin applying these concepts in your classes!