Program to Calculate Area and Circumference of Circle in Java Example

This example is used to calculate the area and circumference of a circle with given radius. The class Circle contains the field radius and methods setData (), area ()and circumference ().The statement.

Circle obj = new Circle();

creates a Circle object in memory and assign it to the reference variable obj,

The statement,

obj.setData(3.5) ;

assigns the radius field of the Circle object to 3.5 using the reference variable obj.

The statement,

obj.area ();

obj.circumference() ;

calculates the area and circumference of the corresponding Circle object, which is finally displayed.

class circle


{


     double radius; //radius of circle


     void setData(double r)


     {


        radius = r;


     }


     void area ()


     {


        double circleArea = Math.PI * radius *radius;


        System.out.println("Area of circle is = " + circleArea);


     }


     void circumference()


     {


        double cir = 2 * Math.PI * radius ;


        System.out.println("circumference of circle is = " + cir);


     }


     


  }


  public class AreaAndCircumference


{


     public static void main(String[] args)


     {


      


        circle obj = new circle();


        obj.setData(3.5 );  //call setData method


        obj.area( );  //call area method


        obj.circumference( );  //call circumference method


     }


}