java/w5/Shapetest.java

package com.example.shape;

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 Shapetest {
    public static void drawShape(Shape s) {
        s.draw();
    }
    
    public static void main(String[] args) {
        Shape circle = new Circle();
        drawShape(circle);
        
        Shape rectangle = new Rectangle();
        drawShape(rectangle);
        
        Shape general = new Shape();
        drawShape(general);
    }
}