import static java.lang.System.out;public class ShapeDemo{ public static void main(String[] args){ Shape shape=new Circle(5); out.println(shape.area()); }} Shape{ double area();}class Circle implements Shape{ private double r; public Circle(double _r){ this.r=_r; } @Override public double area(){ return Math.PI*r*r; }}
发布时间:2024-05-15 09:48:28