6-13/6-14/6-15

//6-13
#include<iostream>

using namespace std;
class Point
{
public:
    Point(int x=0,int y=0):x(x),y(y){}
    int getX() const {return x;}
    int getY() const {return y;}
private:
    int x,y;
};
int main()
{
    Point a(4,5);
    Point * p1=&a;

    int (Point::*funcPtr)() const=&Point::getX;

    cout<<(a.*funcPtr)()<<endl;
    cout<<(p1->*funcPtr)()<<endl;
    cout<<a.getX()<<endl;
    cout<<p1->getX()<<endl;

    return 0;
}

 1 #include <iostream>
 2 //6-14
 3 using namespace std;
 4 
 5 class Point
 6 {
 7 public:
 8     Point(int x=0,int y=0):x(x),y(y)
 9     {
10         count++;
11     }
12     Point(const Point &p):x(p.x),y(p.y)
13     {
14         count++;
15     }
16     ~Point()
17     {
18         count--;
19     }
20     int getX() const
21     {
22         return x;
23     }
24     int getY() const
25     {
26         return y;
27     }
28     static int count;
29 private:
30     int x,y;
31 };
32 int Point::count=0;
33 int main()
34 {
35     int *ptr=&Point::count;
36     Point a(4,5);
37     cout<<"Point A:"<<a.getX()<<","<<a.getY();
38     cout<<"Object count= "<<Point::count<<endl;
39     Point::count=100;
40     Point b(a);
41     cout<<"Point B: "<<b.getX()<<", "<<b.getY();
42     cout<<"Object count="<<*ptr<<endl;
43 
44     return 0;
45 }

 1 #include <iostream>
 2 //6-15
 3 using namespace std;
 4 
 5 class Point
 6 {
 7 public:
 8     Point(int x=0,int y=0):x(x),y(y)
 9     {
10         count++;
11     }
12     Point(const Point &p):x(p.x),y(p.y)
13     {
14         count++;
15     }
16     ~Point(){count--;}
17     int getX() const {return x;}
18     int getY() const {return y;}
19 
20     static void showCount()
21     {
22         cout<<" Object count="<<count<<endl;
23     }
24 private:
25     int x,y;
26     static int count;
27 };
28 
29 int Point::count=0;
30 
31 int main()
32 {
33     void (*funcPtr)()=Point::showCount;
34 
35     Point a(4,5);
36     cout<<"Point A:"<<a.getX()<<", "<<a.getY();
37 
38     funcPtr();
39 
40     Point b(a);
41     cout<<"Point B:"<<b.getX()<<","<<a.getY();
42     funcPtr();
43 
44     return 0;
45 }