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3.2 CLASS IN JAVA
Object-Oriented Programming allows us to develop programs by using the concept of classes and objects. In Java,
the basic structure of a program is organised within a class, meaning the entire program is encapsulated (enclosed)
in a class.
Classes in Java are non-primitive data types that act as a blueprint for creating objects of the same type.
Class comprises characteristics and behaviour. It is a template where many objects share the same features
but having separate specifications for each feature. The syntax to declare a class is as follows:
accessSpecifier class ClassName {
// Data members (attributes or instance variables)
// Methods (functions or behaviors)
}
The description of these components are as follows:
• Access Specifier: Access specifiers define the visibility or accessibility of classes, its methods, and data
members. Common access specifiers include public (accessible from anywhere), private (accessible only
within the class), and protected (accessible within the package and subclasses).
• "class" keyword: The class keyword is used to define a class in Java.
• Class name: The class name is the identifier and is used to refer to a class.
• Data members: Data members are variables defined within a class to represent the properties or state of an object.
• Methods: Methods are functions defined within a class that describe the behaviours or actions that objects of
the class can perform.
Every class must have a Name and attributes, where data members and methods are encapsulated in the second bracket.
Class : Student_class9
Objects : Ajay, Shreyashi
Student_class9
Data Members Methods
Roll_No Academic activities ()
Gender Extra-curricular activities ()
Using the class, two objects are created:
Ajay
Data Members Methods
Roll_No = 1 Academic activities () –
first in studies
Gender = M Extra-curricular activities () –
play cricket
Shreyashi
Data Members Methods
Roll_No = 2 Academic activities () –
Average in studies
Gender = F Extra-curricular activities () –
play badminton, participates in
drama and loves singing.
Elementary Concept of Objects and Classes 43

