类和对象的实现

#includeusing namespace std;int main(){   int i1=1;   double d1=3.21;   cout<<"int->"<"<using namespace std;class person{public:        void Display()        {            cout<<"name: "<<_name<using namespace std;class person{public:        void Display()        {            cout<<"name: "<<_name<using namespace std;class Date{public :        Date(int year,int month,int day)        {           cout<<"构造函数"<using namespace std;class Date{public :        Date(int year,int month,int day)        {           cout<<"构造函数"<using namespace std;class Date{public :        Date(int year,int month,int day);                Date(const Date& d)        {                cout<<"拷贝构造函数"<using namespace std;class Arr{public:        Arr(size_t size)        {            _prt=(int*)malloc(sizeof(int)*size);        }        ~Arr()        {           free(_prt);        }private:        int* _prt;};int main(){   Arr(20);   system("pause");   return 0;}复数类#includeusing namespace std;class Complex{public :        Complex(double real=0,double p_w_picpath=0)        {            cout<<"Complex (double real=0,double p_w_picpath=0)"<_real=d._real;                          this->_p_w_picpath=d._p_w_picpath;                  }                  return *this;        }        void Display()        {                cout<<"Real:"<<_real<<"--Image:"<<_p_w_picpath<