Page 99 - CTS - CSA TP - Volume 2

COMPUTER SOFTWARE APPLICATION - CITS

EXERCISE 94 : Create and use simple classes, objects

and methods in JAVA

Objectives

At the end of this exercise you shall be able to
• know about Create and use simple classes, objects and methods in JAVA
• develop Java programs using classes, objects and Methods.
Requirements

Tools/Materials
• PC/Laptop with Windows OS
• JDK Software
• Text Editor (Visual Studio/Sublime/Notepad)

Procedure

Here’s a brief overview of creating and using simple classes, objects, and methods in Java:
Classes:
• In Java, a class is a blueprint for creating objects. It defines the properties and behaviors of objects.
• A class is declared using the class keyword followed by the class name.

• Inside a class, you define fields (variables) and methods to represent the attributes and behaviors of objects
of that class.
Objects:

• An object is an instance of a class. It represents a real-world entity and has its own state and behavior.
• To create an object in Java, you use the new keyword followed by the constructor of the class.
• The constructor initializes the object and allocates memory for it.
Methods:
• Methods are functions defined within a class that perform certain actions or calculations.

• Methods encapsulate behavior and can be called to perform specific tasks on objects of the class.
• Methods can have parameters (inputs) and return values (outputs).
Below is a simple Java program that demonstrates the creation and usage of classes, objects, and methods:

TASK 1: Calculate the area and perimeter of a rectangle using rectangle class demo
// Define a class named Rectangle
class Rectangle {
// Instance variables
double length;

double width;
// Constructor to initialize the rectangle with length and width
Rectangle(double l, double w) {

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