类和对象试题

Posted 2021-06-11 之墨_

类和对象

public class Square {
    public static void main(String[] args) {
        double S1 = new Circle(2).area();
        double S2 = new Rectangle(3.0,4.0).area();
        System.out.println(S1+"---"+S2);
    }
    static abstract class Shape{
        double x,y;
        public abstract double area();
    }

    static class Circle extends Shape{
        public Circle(double x){
            this.x = x;
        }
        @Override
        public double area() {
            return x*x*Math.PI;
        }
    }
     static class Rectangle extends Shape{
        public Rectangle(double x, double y){
            this.x = x;
            this.y = y;
        }
        @Override
        public double area() {
            return x*y;
        }
    }
}