2547102128李金阳

#include iostreamusing namespace std;class Point {private:int x, y;// 1. 定义静态成员count统计对象个数static int count;public:// 构造函数创建对象时count1Point(int a 0, int b 0) : x(a), y(b) {count;}// 析构函数销毁对象时count-1~Point() {count--;}// 友元函数保留上一题addfriend Point add(Point p, Point q);void show() {cout ( x , y ) endl;}// 2. 静态函数clear把count置0static void clear() {count 0;}// 额外静态函数获取当前count值方便打印查看static int getCount() {return count;}};// 静态变量类外初始化int Point::count 0;// 友元add实现Point add(Point p, Point q) {return Point(p.x q.x, p.y q.y);}int main() {cout 初始count Point::getCount() endl;Point p1(1,2), p2(3,4);Point p3 add(p1,p2);cout 创建3个对象后count Point::getCount() endl;Point::clear(); // 调用静态函数清零cout 调用clear清零后count Point::getCount() endl;return 0;}