Polymorphism: OOPs Concept in Java

Polymorphism in Java is a fundamental concept in object-oriented programming (OOP). It allows programmers to design and create more flexible, reusable, and maintainable code by providing a way to use a single method or object in different ways. In this article, we will explore the different aspects of polymorphism in Java, its types, and examples.

What is Polymorphism?

Polymorphism is derived from the Greek words “poly” meaning many, and “morph” meaning forms. In OOP, polymorphism refers to the ability of an object or method to take on different forms or behaviors. It enables the creation of code that can work with different data types or objects, without the need to create separate code for each type.

Polymorphism is achieved in Java using two main techniques – method overloading and method overriding. In method overloading, multiple methods with the same name but different parameters are created. Method overriding involves creating a method in a subclass that has the same name, return type, and parameters as a method in its superclass.

What are the types of Polymorphism?

Java supports static and dynamic polymorphism, two different types of polymorphism. 

Static Polymorphism

Compile-time polymorphism or method overloading are other names for static polymorphism. When a compiler determines which method to call at compile-time based on the arguments passed to it, the compiler determines which method to call. It is used when the method signatures are different, but the functionality remains the same.

Dynamic Polymorphism

Dynamic polymorphism is also known as run-time polymorphism or method overriding. It occurs when the JVM determines which method to call at run-time based on the object that is being referred to. It is used when the method signature is the same, but the functionality needs to be changed.

Method Overloading

The process of generating numerous methods with the same name but different parameters is known as method overloading. The compiler determines which method to call based on the number, type, and order of arguments passed to it. It is used to provide different ways of calling the same method with different inputs.

Method Overriding

Method overriding is the process of creating a method in a subclass that has the same name, return type, and parameters as a method in its superclass. It is used to provide a specific implementation of a method in the subclass while inheriting the other properties from its superclass.

Abstract Classes and Interfaces

Abstract classes and interfaces are used to implement polymorphism in Java. An abstract class is a class that cannot be instantiated, and it can have abstract methods that must be implemented by its subclasses. An interface is a collection of abstract methods that must be implemented by its implementing class.

Polymorphism Examples

Here are some examples of polymorphism in Java:

• Method overloading: 

The same name has different parameters for the two methods.

public void print(int num){
System.out.printIn(num);
}

public void print(String str) {
System.out.printin(str);
}

• Method overriding: 

Methods in a subclass that have the same name, return type, and parameters as methods in their superclasses.

class Shape {
public void draw() {
System.out.printIn("Drawing a Shape");
     }
}
class Circle extends Shape {
 public void draw

What are the best practices for Polymorphism?

Java’s powerful polymorphism object-oriented programming concept enables objects of various classes to be treated as though they were objects of the same superclass. Polymorphism makes code more flexible and reusable. Here are some best practices for using polymorphism in Java:

1. Create a hierarchy of related classes using inheritance:

Inheritance is the foundation of polymorphism. By creating a superclass and one or more subclasses that inherit from it, you can define a hierarchy of related classes that share common characteristics. This allows you to write code that can work with any object in the hierarchy, regardless of its specific type.

2. To define common behavior, use abstract classes and interfaces:

Abstract classes and interfaces are powerful tools for defining common behavior that can be shared by multiple classes. By defining abstract methods or interface methods, you can ensure that all classes that implement the abstract class or interface will provide the necessary functionality.

3. Use method overriding to implement specific behavior:

The process by which a subclass provides a particular implementation of a method that is already specified in its superclass is known as method overriding. This allows you to tailor the behavior of each subclass to its specific needs while still treating all objects in the hierarchy as if they were of a common type.

4. Use the instanceof operator to check object types:

You can ascertain an object’s type at runtime with the instanceof operator. This can be useful when you need to perform different actions based on the type of object you are working with.

5. Use the super keyword to call superclass methods:

The super keyword allows you to call methods in the superclass from within a subclass. This can be useful when you need to modify the behavior of a superclass method in a subclass but still want to maintain the original behavior of the superclass.

6. Use polymorphism to write flexible, reusable code:

The true power of polymorphism lies in its ability to write code that is flexible and reusable. By writing code that can work with any object in a hierarchy, regardless of its specific type, you can create code that is more robust and easier to maintain.

Conclusion

Polymorphism is a fundamental concept in object-oriented programming that allows for more flexible and efficient code. With the ability to have multiple methods with the same name, but different parameters or behaviors, programmers can write code that is more modular and easier to maintain. In Java, polymorphism is implemented through both compile-time and runtime mechanisms, providing a wide range of possibilities for software development. By understanding the different types of polymorphism in Java and how they can be used effectively, developers can write more robust and efficient code.