OOPs

30. Write a Java program to create a class called Circle with a private instance variable radius. Provide public getter and setter methods to access and modify the radius variable. However, provide two methods called calculateArea() and calculatePerimeter() that return the calculated area and perimeter based on the current radius value.

            class Circle{
                private double radius;
                public double getRadius(){
                    return radius;
                }
                public void setRadius(double r){
                    radius = r;
                }
                double calculateArea(){
                    return (Math.PI * radius * radius);
                }
                double calculatePerimeter(){
                    return (2 * Math.PI * radius);
                }
            }
            class Main{
                public static void main(String[] args){
                    Circle obj = new Circle();
                    obj.setRadius(5);
                    System.out.println("Radius of Circle : " + obj.getRadius());
                    System.out.println("Area : " + obj.calculateArea());
                    System.out.println("Circumference : " + obj.calculatePerimeter());
                }
            }
        

OUTPUT

            Radius of Circle : 5.0
            Area : 78.53981633974483
            Circumference : 31.41592653589793