1 int main(int argc, _TCHAR* argv[])
 2 {
 3     using namespace std;
 4     cout << "PersonPerson p = Person()"
 5          << endl;
 6     Person p = Person("张三", "25");
 7     cout << p.get_name()
 8          << "\n"
 9          << p.get_sex()
10          << endl;
11     //在此方法结束前, p一直可访问
12     return 0;
13 }

 1 int main(int argc, _TCHAR* argv[])
 2 {
 3     using namespace std;
 4     cout << "Person *p = new Person()"
 5          << endl;
 6     Person *p = new Person("张三", "25");
 7     cout << p->get_name()
 8          << "\n"
 9          << p->get_sex()
10          << endl;
11     //主动释放p , 或者调用了析构函数
12     delete p;
13     //应该明确将p指向NULL , 或者调用析构函数释放p
14     p = NULL;
15     cout << "主动释放了Person\n"
16          << p
17          //p已经指向了一个不明的地址，将会报错
18          << p->get_name()
19          << endl;
20     return 0;
21 }