OOPS Concept in Java Explained for Beginners

Java is one versatile programming language that was initially known as ‘Oak.’ The name was later changed to ‘Green,’ followed by ‘Java,’ and its first-ever public version came on the market in 1995. Today Java is used in gaming consoles software development and mobile or desktop applications. The programming language is marked by its popularity, and a survey of 2021 gave 5th position to Java in terms of usage among the worldwide developers.

OOPs, a concept in Java or Object-Oriented Programming is the core concept of this programming language. Understanding its functionality is of utmost importance as it is one of the most widespread coding practices.

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If you’re a beginner in Java, understanding the implementation of the OOPs concept in Java and taking advantage of its features can seem like a minefield. However, this piece makes it easy for you to grasp the key concepts and covers the six essential pillars of OOP. These are objects, classes, abstractions, polymorphism, inheritance, and encapsulations. 

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What is the OOPs concept in Java?

Object-Oriented Programming System (OOP) is a core programming concept based on abstractions, polymorphisms, inheritances, and encapsulations. Using this concept, the users can create objects and corresponding methods to steer those objects. OOPs improves code reusability and readability by efficiently defining the programs of Java.

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Understanding objects

The various instances of a class are known as objects, having both behaviour and state. These are abstract data types, simply meaning that some operations and values explain the behaviour of an object. 

Objects are real entities and can be both logical and physical data. They have an address and take up memory space. For instance, trees, tables, chairs, dogs, etc., are all objects. If animals are considered objects, their state would be their name, colour, etc. Their behaviour would be tail wagging, running, eating, etc.

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Understanding classes

Among the basic concepts of Java are classes, which is a group of similar objects. They are logical quantities, not physical entities, and do not take up much memory space. For instance, if you have created a class, namely “Exotic fruits”, its objects will be Rambutan, Durian, Persimmon, Sapodilla, Dragon fruit, etc.

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Four pillars of OOPs concept in Java


Polymorphism in OOPs is the capacity of an object, function or variable to take on numerous forms. Polymorphism is a process which carries out one action in multiple ways. For example, a child can take on a variety of careers. They can be a writer, engineer, doctor, teacher, etc. Thus, this child has multiple ways to exist depending on various situations. The same concept applies to Polymorphism in OOPs. Another example can be the word ‘lost’, which has one meaning if used with ‘temper’, but another meaning when used with ‘wallet’.


Encapsulation in OOPs means data wrapping under a single umbrella. This process is responsible for binding the code with the data in one unit, keeping them safe from outside interference or misuse. In encapsulation, the class variables are hidden from other classes. The perfect example to explain encapsulation in OOPs would-be students of a school who can only exist within a class and not outside it.

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The third pillar of the OOPs concept in Java is an abstraction, which explains that essential features are represented, excluding the background details. Thus, data hiding is the primary purpose of abstraction, reducing efforts and complexity in programming. To understand the concept, we can take the example of an application form filled out by a student. Any application form demands information like students’ name, class, date of birth, guardian name, address, etc. However, all information is not required for application. Thus, an application form fetches information, selects the essential bit and removes the unnecessary ones. This is the same process as an abstraction.


The fourth pillar in OOPs is inheritance, which, as the name indicates, inherits the properties and behaviour of another object. This pillar of OOPs represents a typical parent-child relationship because, much like children inherit certain features from their parents, new classes are built on the features of existing classes. For instance, if the parent class is ‘Vehicles’, common properties such as size, type or colour can be taken to build new classes like bike, car, bicycle or bus.

OOPs: What are the advantages of using it?

OOPs, a concept in Java, offers many advantages. These are:

Data redundancy

Data redundancy means that one data is at hand twice. In OOPs, data redundancy is perhaps the biggest advantage if the user wants to use one particular function in more than one class.


One core tenet of the OOPs concept in Java is inheritance, which allows the inheritance of properties from a parent object, thus avoiding re-writing the same class attributes multiple times. Hence, it saves ample time and effort for the user.


Owing to the abstraction pillar in OOPs, the user has access to limited data. The user is exposed to only the necessary bits, while the remainder is not exposed, ensuring security maintenance.

Easy troubleshooting

For an amateur, it can be challenging to find a bug if there are code errors in any standard programming language. But with OOPs, a user knows where the bug is whenever there is an error. Thus troubleshooting is easier because the users don’t have to check the code line-by-line.

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The bottom line

Learning about these concepts is only the tip of the iceberg because this piece explains the core concepts for beginners. These concepts offer code redundancy and maintenance, along with re-usability.

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Polymorphism in OOPs: What is it?

Polymorphism in OOPs is a process which lets the user perform one particular action in a multitude of ways. Put simply. Polymorphism allows a user to have more than one implementation by defining only one interface. There are two types of polymorphism in OOPs, namely: 1) Compile-time or static binding polymorphism 2) Runtime or dynamic binding polymorphism

What are the basic ideas of OOPs?

The OOPs concept in Java has four pillars, which are: Inheritance,Polymorphism, Encapsulation ,Data abstraction

Why is the OOPs concept in Java used?

OOPs are used because it provides an array of benefits, like: Code maintenance, Security, Re-usability, Problem-solving, Easy troubleshooting, Data Redundancy, Design benefits

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