3. DADOS/OBJETOS ANTI-SIMETRIA

Listing 6-5

Procedural Shape

public class Square {
public Point topLeft;
public double side;
public class Rectangle {
public Point topLeft;
public double height;
public double width;
public class Circle (
public Point center;
public double radius;
public class Geometry {
public final double PI = 3.141592653589793;
public double area(Object shape) throws NoSuchShapeException
if (shape instanceof Square) {
Square s = (Square)shape;
return s.side * s.side;
else if (shape instanceof Rectangle) {
Rectangle r = (Rectangle)shape;
return r.height * r.width;
else if (shape instanceof Circle) {
Circle c = (Circle)shape;
return PI * c.radius * c.radius;
throw new NoSuchShapeException();

Listing 6-6

Polymorphic Shapes

public class Square implements Shape {
private Point topLeft;
private double side;
public double area() {
return side*side;
} }
public class Rectangle implements Shape {
private Point topLeft;
private double height;
private double width;
public double area() {
return height * width;
 


public class Circle implements Shape {
private Point center;
private double radius;
public final double PI = 3.141592653589793;
public double area() {
return PI * radius * radius;