基础题—Shape类

class Shape {
    public void draw() {
        System.out.println("绘制形状");
    }
}
class Circle extends Shape {
    @Override
    public void draw() {
        System.out.println("绘制圆形");
    }
}
class Rectangle extends Shape {
    @Override
    public void draw() {
        System.out.println("绘制矩形");
    }
}
public class ShapeDemo {
    public static void drawShape(Shape s) {
        s.draw();
    }
    public static void main(String[] args) {
        Shape circle = new Circle();
        Shape rectangle = new Rectangle();
        drawShape(circle);
        drawShape(rectangle);
    }
}