Understand Inheritance and Polymorphism in Java

Have you ever wondered how inheritance and polymorphism differ in object-oriented programming? Polymorphism permits adaptable interactions through shared interfaces, whereas inheritance establishes class hierarchies for code reuse. Let’s learn more!

Polymorphism makes use of this structure to allow for flexible and interchangeable object interactions, while inheritance establishes an organised class system based on relationships between general and more specialised classes. Both help programmers produce more readable, concise, and effective code and are essential for the creation of scalable, maintainable, and efficient software. We will fully comprehend the distinctions between them in this blog!

 

Aspect Inheritance Polymorphism
Definition By using the inheritance mechanism, a new class can inherit the methods and properties of an existing class by deriving from it. Through the use of interfaces and abstract classes, polymorphism enables objects of various classes to be considered as objects of a common super class.
Purpose used to create a parent-child relationship between classes and gain code reusability. used to allow distinct classes to be treated as instances of the same class, especially when their methods have the same name, in order to achieve code flexibility.
How It Works In addition to inheriting characteristics and methods from the parent class, the child class is also allowed to have custom attributes and behaviours. relates to methods that share the same name but have various possible behaviours across different classes. At runtime, the precise method that is called is decided.
Types Single inheritance, multiple inheritance, multilevel inheritance, hierarchical inheritance, hybrid inheritance. Overloading (compile-time polymorphism) and overriding (runtime polymorphism).
Key Principle “IS-A” relationship. For example, a Dog is an Animal. “CAN-DO” relationship. For example, a Printer can print in different ways.
Implementation accomplished by means of class definitions. Languages such as Java make use of the extends keyword. accomplished by overloading and overriding the method. Frequently, interfaces or abstract classes are used.
Usage Example A class Vehicle is the ancestor of a class Car. The Car will have all of the features and functions of the Vehicle in addition to its own special features and functions. Depending on whether a function draw is being used to draw a circle, square, or triangle, there are several possible implementations. Every shape will use draw in a unique way.
Flexibility When the class is created, it is defined and static. It can offer a more adaptable interface for object interactions and is dynamic.
Limitation Intricate and challenging to handle deep inheritance structures might arise. It can cause confusion regarding which method is being called if it is not handled correctly.

 

What is Inheritance?

One of the core ideas of object-oriented programming (OOP) is inheritance. It describes the process by which a class (also called a parent class or superclass) gains access to the methods and fields of another class (also called a child class or subclass). 

Key Points about Inheritance

Reusing existing code is made possible by inheritance. Code reuse and redundancy are minimised when the child class inherits all of the parent class’s protected and public properties and methods.
It is possible to add new functionality to existing code without changing it by using inheritance. This is very helpful when altering the behaviour of existing features or adding new ones in an existing class hierarchy.
Polymorphic behaviour, in which a subclass is regarded as an instance of the parent class, is made possible by inheritance. This is essential for putting polymorphism into practice in OOP.
It aids in establishing a domain’s natural class hierarchy. For instance, the Car, Truck, and Motorcycle classes may all descend from the Vehicle class.

A child class can override a method specified in its parent class through inheritance, allowing for unique implementations that differ from the parent class.
Different programming languages have different implementations of inheritance. Languages such as Python and C++ provide multiple inheritance (a class can inherit from numerous parent classes), whereas languages like Java and C# only allow single inheritance (a class can inherit from one parent class). 

What is Polymorphism?

One of the fundamental ideas of object-oriented programming (OOP) is polymorphism, which is the capacity of many objects to react differently to the same message (or method call). The Greek words “poly” (meaning “many”) and “morph” (meaning “form”) are the source of the phrase “polymorphism”. It permits objects of various classes to be regarded as belonging to a common superclass while programming.

There are 2 main types of Polymorphism in OOP:

  1. Compile-time polymorphism, often known as static polymorphism, is accomplished by operator and method overloading. When several methods share the same name but have different parameters (number, type, or both), it happens. The method signature is used at build time to determine which method should be used. For instance, you might have several copies of the add() function in a class, each accepting a different kind or quantity of parameters. 
  2. Method overriding, which is the process of giving a method in a subclass the same name and type signature as a method in its superclass, allows for Run-Time Polymorphism (also known as Dynamic Polymorphism). The object calling the method determines at runtime which particular version of the method is executed. Typically, interfaces in languages like Java and a feature called “inheritance” are used to do this.

Key Points on Polymorphism

Interfaces, which describe methods that any class can implement, are frequently used alongside polymorphism. It is up to the classes that implement these interfaces to handle the implementation details.
More generalised and abstract coding is possible with it. Programmers have the ability to construct code that remains unchanged upon the creation of a new subclass from a superclass.
Writing code that makes advantage of an object’s interface makes it adaptable and capable of working with newly created subclasses that weren’t there when the code was first developed.
Thus, two essential ideas in object-oriented programming (OOP) are inheritance and polymorphism. They function differently and have different functions.

Polymorphism is often used with interfaces, which define methods that any class can implement. The classes that implement these interfaces are responsible for handling the specifics of implementation.
It allows for more abstract and generic coding. It is possible for programmers to write code that doesn’t change when a new subclass is created from a superclass.
When code is written to take use of an object’s interface, it becomes flexible and may be used with newly-created subclasses that were not present when the code was written.
Thus, polymorphism and inheritance are two fundamental concepts in object-oriented programming, or OOP. They serve distinct purposes and operate in diverse ways.

What is Java Certification?

An official validation of one’s proficiency in Java programming, obtained through reputable organisations like Oracle, is called a Java certification. These certificates are offered at multiple levels to accommodate novice, intermediate, and expert programmers, covering a wide range of Java programming topics, from basic concepts to advanced subjects. For those looking to pursue such a certification, options like a Java certification course in Greater Noida, Delhi, Pune and other parts of India can be explored to find suitable preparation and training opportunities.

 

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