#include <iostream>
using namespace std;class Point{
public:int x;int y;Point(int x1, int y1) : x(x1), y(y1)  //成员初始化列表{ }int getDistance() {return x * x + y * y;}
};void changePoint1(Point point)    //使用对象作为函数参数
{point.x += 1;point.y -= 1;
}void changePoint2(Point *point)   //使用对象指针作为函数参数
{point->x += 1;point->y -= 1;
}void changePoint3(Point &point)  //使用对象引用作为函数参数
{point.x += 1;point.y -= 1;
}int main()
{Point point[3] = {Point(1, 1), Point(2, 2), Point(3, 3)};Point *p = point;changePoint1(*p);cout << "the distance is " << p[0].getDistance() << endl;p++;changePoint2(p);cout << "the distance is " << p->getDistance() << endl;changePoint3(point[2]);cout << "the distance is " << point[2].getDistance() << endl;return 0;
}

第一个不应该是：
22+00 输出4吗？