t5-2.cpp

学习c++的ppt

#include <iostream.h>
class Point  {
        int x, y;
    public:
        Point(int ux=0, int uy=0) 
        {   x = ux; y = uy;
        }
        int  getx() { return x; }
        int  gety() { return y; }
};
class Circle  {
    private:
        Point  p;
        int  r;
    public:
        Circle(int ux=0, int uy=0, int ur=0):p(ux, uy), r(ur) { }
        float  area() 
        {   return (float)3.1415*r*r;
        }
};
void main()
{   Circle  a(50, 50, 10), b;    // 直接进行初始化 b=a 或 b(a)
    cout << "A 面积是：" << a.area() << endl;
    cout << "B 面积是：" << b.area() << endl;
    b = a;
    cout << endl;
    cout << "新的 B 面积是：" << b.area() << endl;
}