To bridge this gap, every object is first generalized into a class of things. Objects are the first things to think about when designing a program, as they are the units of code that are finally derived from the process. Let us continue with the basic concepts of OOPs. The blueprints are then used as the basis for creating instance objects.

A program is categorized into reusable pieces of code called blueprints (typically called classes). In OOPs, classes and objects are used as the fundamental analysis and design units. It is a method for storing data with the procedures required for processing them, based on a mathematical discipline known as 'abstract data types”. This extends keyword is used in the definition of the class and is followed by the class name that is to be inherited.Object-oriented programming (OOPs) is a technique of programming that consists of identifying classes of objects that have a strong connection to the methods (functions) associated with them. In Java, inheritance is achieved by using the “extends” keyword. The inherited class is known as the “super” class in Java.īy inheriting the class, the subclass not only inherits the properties but also reuses the code as the programmer need not once again write the code when it can directly inherit it using inheritance.

The class that inherits the properties of another class is called the subclass. The properties that can be inherited include data members and methods of the class. Inheritance is a mechanism in Java in which one class can inherit the properties of another class. Through inheritance, Java promotes the reusability of code. Inheritance is one of the most important characteristics of OOP. We will learn more about classes and objects in our specific OOP tutorials topics. Once the objects are created we assign data to both the object properties.įinally, we print the object contents using ‘.’ (dot) operator. Note that these objects are created using a new operator. Then in the main method, we declare two class objects i.e. In the above class, we have defined a class Student with two properties roll_No and student_name. Student2.roll_No+' '+student2.student_name) Student1.roll_No+' '+student1.student_name) Given below is a program that demonstrates class and object. Here the identity of the object is a pig. Then we can define an object of this class as follows:

Identity: Identifies the object by giving it a unique name.įor example, if we have a class PetAnimals.

Methods also define how the objects communicate.

Behavior: Methods represent the behavior of an object.

A state: The properties or attributes of an object at a particular time.

These objects often communicate with each other by passing messages to each other through methods. So a class which is a blueprint may be used to create many objects. In Java, an object is an instance of a class. Then we define the instances of this class called objects.Ī class has many components as shown in the following figure.Īn object represents a real-life entity. It essentially defines a common type consisting of properties and methods that operate on these properties for this common type. Objects are created from these blueprints. Object & ClassĪ class can be defined as a design prototype or a blueprint. Let’s discuss each of these Java OOP concepts in detail. Here we are going to discuss how Java supports the following OOP features. Recommended Reading => OOP Interview Questions and Answers Thus in this tutorial, we will discuss the main features of OOP concerning Java. Java has a root class called Object from which the entire functionality of Java is derived. In Java, everything is based on the object. Java is the most sought after programming skill at present.

Object-Oriented Programming (OOP) In Java

In this tutorial, we will discuss the basics of OOP concerning Java language. Smalltalk, C++, Java, etc are some of the object-oriented programming languages. In OOP, the objects communicate with each other through messages.Īny OOP language supports the following features:Īll these features ensure that the data is secured and at the same time we can also write robust applications. This way, the data is protected from the outside world by having the methods inside the object. This object bundles up data and the methods that operate on this data in one unit. The object-oriented programming (OOP) revolves around objects i.e. Object-oriented programming languages emphasize on data more than the functions.

Oops concepts in java