填空题

下列程序的运行结果是______。 #include＜iostream.h＞ class Sample { int a; public: Sample(int aa=0){a=aa;} ～Sample( ){cout~＜＜"Sample="＜＜a＜＜’’;} }; class Derived:public Sample { int b; public: Derived(int aa=0,int bb=0):Sample(aa)(b=bb;} ～Derived( ){cout＜＜"Derived="＜＜b＜＜";} }; void main( ) { Derived d1(9); }