What is Polymorphism?
Polymorphism is a fundamental concept in object-oriented programming (OOP) that allows objects of different classes to be treated as objects of a common superclass. It is derived from the Greek words “poly,” meaning “many,” and “morph,” meaning “form.” In simpler terms, polymorphism enables us to perform different actions using a single interface.
Basic Concepts of Polymorphism
Polymorphism is based on two key principles – inheritance and overriding. Let’s explore these concepts further.
Inheritance: Inheritance is a mechanism in OOP that allows a class (called a child or derived class) to inherit properties and behaviors from another class (called a parent or base class). This is achieved using the “extends” keyword in languages like Java.
When a child class inherits from a parent class, it not only inherits the attributes and methods but also the ability to be used in the same way as its parent class. This is where polymorphism comes into play.
Overriding: Overriding is the process of providing a different implementation for a method in the child class that is already defined in the parent class. It allows the child class to customize or extend the behavior inherited from the parent class.
In polymorphism, the methods that are overridden in the child class can be invoked using the same interface defined in the parent class. This means that the same method call can have different behaviors, depending on the object type at runtime.
To better understand polymorphism, let’s consider a real-life example.
Think about different types of vehicles, such as cars, bicycles, and motorcycles. Although they have their specific characteristics and functionalities, they all have one thing in common – they are vehicles. You can perform certain actions on all these vehicles, such as accelerating, decelerating, or applying brakes.
In an object-oriented design, we can define a common superclass called “Vehicle” and specific subclasses for each type of vehicle. Each subclass can override the common methods defined in the “Vehicle” class, reflecting their unique behaviors.
By utilizing polymorphism, we can write a single piece of code that can handle an array or list of vehicles at runtime. Regardless of the specific type of vehicle, we can call the same methods on each object and it will execute the appropriate behavior defined in the corresponding subclass.
This flexibility and extensibility provided by polymorphism make code more maintainable, reusable, and adaptable to future changes. It allows us to write cleaner and more efficient code without the need for repetitive conditionals or case statements.