C++语言基础 例程 对象的动态建立和释放

贺老师的教学链接  本课讲解

对象的动态建立和释放

#include<iostream>
using namespace std;
class Box
{
public:
    Box(int w,int l,int h);
    ~Box();
    int width;
    int length;
    int height;
};
Box::Box(int w,int l,int h)
{
    width=w;
    length=l;
    height=h;
    cout<<"========调用构造函数=======\n";
}
Box::~Box()
{
    cout<<"========调用析构函数=======\n";
}
int main()
{
    Box * p=new Box(12,13,15);
    cout<<p->width<<"\t";
    cout<<p->length<<"\t";
    cout<<p->height<<endl;
    delete p;
    return 0;
}

建立指针数组

#include <iostream>
using namespace std;
class Time
{
public:
    Time(int,int,int);
    void get_time( );
private:
    int hour,minute,sec;
};
Time::Time(int h,int m,int s):hour(h),minute(m),sec(s) {}
int main()
{
    const int N = 100;
    Time *t[N]= {NULL};
    int i;
    i=3;
    if(t[i]==NULL)
        t[i] = new Time(10, 10,10);
    if(t[i]!=NULL)
        delete t[i];
    return 0;
}