A67604. 关于下面代码，说法错误的是（ ）。1 class Shape {

关于下面代码，说法错误的是（ ）。

1 class Shape { 
2 protected: 
3  string name; 
4
5 public: 
6  Shape(const string& n) : name(n) {} 
7
8  virtual double area() const { 
9   return 0.0; 
10  } 
11 }; 
12
13 class Circle : public Shape { 
14 private: 
15  double radius; // 半径
16
17 public: 
18  Circle(const string& n, double r) : Shape(n), radius(r) {} 
19
20  double area() const override { 
21   return 3.14159 * radius * radius; 
22  } 
23 }; 
24
25 class Rectangle : public Shape { 
26 private: 
27  double width; // 宽度 
28  double height; // 高度 
29
30 public: 
31  Rectangle(const string& n, double w, double h) : Shape(n), width(w), height(h) 
{} 
32
33  double area() const override { 
34   return width * height; 
35  } 
36 }; 
37
38 int main() { 
39  Circle circle("MyCircle", 5.0); 
40  Rectangle rectangle("MyRectangle", 4.0, 6.0); 
41
42  Shape* shapePtr = &circle; 
43  cout << "Area: " << shapePtr->area() << endl; 
44
45  shapePtr = &rectangle; 
46  cout << "Area: " << shapePtr->area() << endl; 
47 
48  return 0; 
49 }