分享一个挺有意思的代码：

1 #include 
      
        2 using namespace std; 3  4 struct Point { 5     static int cnt; 6     Point() { 7         ++cnt; 8         cout << "There is " << cnt << " item(s)." << endl; 9     }10     ~Point() {11         --cnt;12         cout << cnt << " item(s) remains." << endl;13     }14 } ;15 int Point::cnt;16 17 int main() {18     Point a, b;19     delete (new Point());20     Point c, d;21     return 0;22 }
      

java是可以直接在类中初始化的，不过C++的初始化要在结构体外完成，否则会在链接的时候发生找不到对象的错误。

1 #include 
      
        2 using namespace std; 3  4 class TheOnlyInstance { 5     public: 6         static TheOnlyInstance *GetTheOnlyInstance(); 7         static int Parameter; 8     protected: 9         TheOnlyInstance() {}10 } ;11 12 //int TheOnlyInstance::Parameter = 2;13 14 TheOnlyInstance *TheOnlyInstance::GetTheOnlyInstance() {15     static TheOnlyInstance objTheonlyInstance;16     int Parameter = 1;17     return &objTheonlyInstance;18 }19 20 int main() {21     //cout << TheOnlyInstance::Parameter << endl;22     cout << TheOnlyInstance::GetTheOnlyInstance() << endl;23     cout << TheOnlyInstance::Parameter << endl;24     return 0;25 }
      

 

 

——Written by Lyon