写出下列程序的运行结果
#include<iostream.h> class Datal{ int x; public: Data(int x){ Data::X=X; cout<<"Data cons."<<endl; } ~Data(){cout<<"Data des."<<endl;} }; class Base{ Data dl; public: Base(int x);dl(x){cout<<"Base cons."<<endl;} ~Base(){cout<<"Base des."<<endl;} }; class Derived:public Base{ Data d2; public: Derived(int x):Base(x), d2(x){cout<<"Derived cons."<<endl;} ~Derived(){cout<<"Derived des."<<endl; }; void main(){ Derived obj(5); }