CLASS FUNDAMENTAL

A class is simply a template.
An object is created to give life to the various attributes of a class..

Note:- In Java a class template takes no memory, Memory is allocated when object is created.

Program :- Calculate Area of Rectangle

class Rectangle

{

double width;

double height;

double area();

{

return width height;

}

}

class RectangleDemo

{

public static void main(String args[])

{

Rectangle rec1=new Rectangle();

double area;

rec1.width=10;

rec1.height=20;

area=rec1.area();

System.out.println("Area"+area);

}

}

OUTPUT:-

Area 200.0

Note :- The line written in yellow line is used for creating object of a class..

             where

              rec1- Reference variable

              new- New operator

              Rectangle()- Constructor