C++——动态内存分配2-创建对象数组

//创建对象数组

#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;

};

int main()

{

Point *Ptr=new Point[2]; //创建对象数组

Ptr[0].Move(5,10); //通过指针访问数组元素的成员

Ptr[1].Move(15,20); //通过指针访问数组元素的成员

cout<<"Deleting..."<<endl;

delete[ ] Ptr; //删除整个对象数组

}//运行结果：

Default Constructor called.

Deleting...

Destructor called.

//动态数组类，不需要预先设计好数组的大小

#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(int n)//根据实际来调整数组大小

{ numberOfPoints=n; points=new Point[n]; }

~ArrayOfPoints()//

{ cout<<"Deleting..."<<endl;

numberOfPoints=0; delete[] points; }

Point& Element(int n)//返回所需要的元素

{ return points[n]; }

private:

Point *points;

int numberOfPoints;

};

int main()

{

int number;

cout<<"Please enter the number of points:";

cin>>number;

ArrayOfPoints points(number); //创建对象数组

points.Element(0).Move(5,10); //通过指针访问数组元素的成员

points.Element(1).Move(15,20); //通过指针访问数组元素的成员

}

//运行结果如下：

Please enter the number of points:2

Default Constructor called.

Deleting...

Destructor called.