在创建对象时调用构造函数，在释放对象时调用析构函数，在一般情况下，调用析构函数与创建对象的顺序相反。构造函数与析构函数的调用顺序。-Call the constructor and destructor is called when the object is released when the object was created, in the general case, call the destructor create objects in reverse order. Constru