每日代码系列（15）

abstract class Shape {
  public abstract float area();
  public abstract void printArea();
}
class Rectangle extends Shape {
  int width;
  int length;
  public Rectangle(int newWidth,int newLength) {
    width=newWidth;
    length=newLength;
  }
  public float area() {
    float area=width*length;
    return area;
  }
  public void printArea() {
    System.out.println("矩形的面积: "+area());
  }
}
class Circle extends Shape {
  final float PI=3.14F;
  int radius;
  public Circle(int newRadius) {
    radius=newRadius;
  }
  public float area() {
    float area=PI*radius*radius;
    return area;
  }
  public void printArea() {
    System.out.println("圆的面积: "+area());
  }
}
class ChouXiang {
  public static void main(String[] args) {
    Rectangle s1=new Rectangle(3,4);
    Circle s2=new Circle(2);
    s1.printArea();
    s2.printArea();
  }
}

有什么意见，下面评论区说哈。