C++——深拷贝
要实现深拷贝就需要自己编写拷贝构造函数。
深拷贝
#include<iostream>
using namespace std;
class Point
{ public:
Point()
{ X=Y=0; cout<<"Default Constructor called."<<endl; }
Point(int xx,int yy)
{ X=xx; Y=yy; cout<< "Constructor called."<<endl; }
~Point()
{ cout<<"Destructor called."<<endl; }
int GetX() {return X;}
int GetY() {return Y;}
void Move(int x,int y)
{ X=x; Y=y; }
private:
int X,Y;
};
class ArrayOfPoints
{ public:
ArrayOfPoints(ArrayOfPoints& pointsArray);
ArrayOfPoints(int n)
{ numberOfPoints=n; points=new Point[n]; }
~ArrayOfPoints()
{ cout<<"Deleting..."<<endl;
numberOfPoints=0; delete[] points;
}
Point& Element(int n)
{ return points[n]; }
private:
Point *points;
int numberOfPoints;
};
ArrayOfPoints ::ArrayOfPoints(ArrayOfPoints& pointsArray)//自己写拷贝构造函数，用本类对象的引用作参数
{ numberOfPoints=pointsArray.numberOfPoints;
points=new Point[numberOfPoints];
for (int i=0; i<numberOfPoints; i++)
points[i].Move(pointsArray.Element(i).GetX(),pointsArray.Element(i).GetY());
}
int main()
{
int number;
cout<<"Please enter the number of points:";
cin>>number;
ArrayOfPoints pointsArray1(number); //创建对象数组
pointsArray1.Element(0).Move(5,10); //通过指针访问数组元素的成员
pointsArray1.Element(1).Move(15,20); //通过指针访问数组元素的成员
ArrayOfPoints pointsArray2(pointsArray1); //创建对象数组副本
cout<<"Copy of pointsArray1:"<<endl;
cout<<"Point_0 of array2: "
<<pointsArray2.Element(0).GetX()
<<", "<<pointsArray2.Element(0).GetY()<<endl;
cout<<"Point_1 of array2: "
<<pointsArray2.Element(1).GetX()
<<", "<<pointsArray2.Element(1).GetY()<<endl;
pointsArray1.Element(0).Move(25,30); //通过指针访问数组元素的成员
pointsArray1.Element(1).Move(35,40); //通过指针访问数组元素的成员
cout<<"After the moving of pointsArray1:"<<endl;
cout<<"Point_0 of array2: "
<<pointsArray2.Element(0).GetX()
<<", "<<pointsArray2.Element(0).GetY()<<endl;
cout<<"Point_1 of array2: "
<<pointsArray2.Element(1).GetX()
<<", "<<pointsArray2.Element(1).GetY()<<endl;
} //程序的运行结果如下：
Please enter the number of points:2
Default Constructor called.
Default Constructor called.
Default Constructor called.
Default Constructor called.
Copy of pointsArray1:
Point_0 of array2: 5, 10
Point_1 of array2: 15, 20
After the moving of pointsArray1:
Point_0 of array2: 5, 10
Point_1 of array2: 15, 20
Deleting...
Destructor called.
Destructor called.
Deleting...
Destructor called.
Destructor called.
