/** Sphere class
 *
 * @author Ivan Filipov
 * @version 25Jun2019
 *
 */
public class Sphere {

	double radius;

	Sphere(){
		radius = 1;
	}

	Sphere(double newRadius){
		radius = newRadius;
	}

	double getSurfaceArea() {
		return (Math.PI * Math.pow(radius, 2)) * 4;
	}

	boolean checkRadius() {
		if(radius > 0) {
			return true;
		}
		return false;
		}


public static void main(String[] args) {

	Sphere sphere1 = new Sphere(12);

	if(sphere1.checkRadius()) {
		System.out.println("Sphere 1: ");
		System.out.println("Radius: " + sphere1.radius);
		System.out.println("Surface area: " + sphere1.getSurfaceArea());
		System.out.println("checkRadius(): " + sphere1.checkRadius());
	}

	Sphere sphere2 = new Sphere(-15);

	if(sphere2.checkRadius()) {

		System.out.println("Sphere 2: ");
		System.out.println("Radius: " + sphere2.radius);
		System.out.println("Surface area: " + sphere2.getSurfaceArea());
		System.out.println("checkRadius(): " + sphere2.checkRadius());

		}
	}
}