以下程序执行结果是 ( )。 #include <iostream.h> class Base { public virtual void fun() { cout<<"B"; } }; class Derived { public: Derived() { cout<<"D"; } virtual void fun(){ Base::fun(); cout<<"C"; } } int main () { Base *ptr; Derived obj; ptr=&obj; p->fun ( ); return 0; }
A.DBC
B.DCB
C.BDC
D.CBD
第1题:
按解释中的要求在下列程序划线处填入的正确语句是:() #include <iostream.h> class Base{ public: void fun() {cout<<"Base::fun"<<endl;} }; class Derived:public Base{ public: void fun() { _______________________//在此空格处调用基类的函数fun() cout<<"Derived::fun"<<endl;} };
A.fun();
B.Base.fun();
C.Base::fun();
D.Base->fun();
第2题:
以下程序执行后的输出结果是 ( )。 #include <iostream.h> class Basel { public: void fun(){ cout<<"Basel"<<end1; } }; class Base2 { public: void fun() { cout<<"Base2"<<end1; } } class Derived : public Basel,public Base2 { }; void main() { Derived Obj; Obj.fun(); }
A.Basel
B.Base2
C.BaselBase2
D.程序产生二义性
第3题:
下面程序的结果是 ______。 #include<iostream.h> class A{ public: virtual void fun()=0{}; }; class B:public A{ public: void fun () {cout<< "new file" ;} }; class C: public A{ public: void fun (){cout<<"open file"<< " " } }; class D: public A{ public: void fun () {cout<< "save file\n" ;} }; void main() { A a,*p; B b; C c; D d; p=&c; p->fun (); p=&b; p->fun (); p=&d; p->fun(); }
A.new file open file save file
B.new file new file new file
C.编译出错
D.open file new file save file
第4题:
下面程序的运行结果是 #include<iostream.h> class base{ protected: int a; public: base( ){cout<<"0";} }; class basel:virtual base { public: base1( ){cout<<"1";} }; class base2:virtual base{ public:
A.123
B.3120
C.312
D.3012
第5题:
下列程序的运行结果是______。
include<iostream.h>
class Base
{
public:
void f(int x){cout<<“Base:”<<x<<endl;}
);
class Derived:public Base
{
public:
void f(char*str){cout<<“Derived:”<<str<<endl;}
};
void main(void)
{
Base*pd=ne
第6题:
下面程序的结果是 #include<iostream.h> class A { public: A( ) {cout<<"construtA"<<endl;} virtual~A( ) {cout<<"destructA"<<endl;}}; class B:public A {}; class C:public A {}; c
A.constructA destructA
B.constructA constructA destructA destructA
C.constructA constructA constructA destructA destructA destructA
D.constructA onstructA constructA constructA destructA destructA destructA destructA
第7题:
下面程序的运行结果是( )。 #include<iostream.h> class base{ protected: int a; public: base(){cout<<“0”;} }; Class basel:Virtual base{ public: basel(){cout<<“1”;} }; Class base2:virtual base{ public: base2(){cout<<“2”;)
A.0123
B.3120
C.0312
D.3012
第8题:
下面程序的输出结果为:Base:: fun,请将程序补充完整。
include <iostream.h>
class Base{
public:
【 】 fun(){cout<<"Base::fun"<<end1:}
class Derived : public Base{
public:
【 】 fun(){ cout<<"Derived::fun"<<end1; }
};
int main()
{
Base a,*pb;
Derived b;
pb = &b;
pb->fun();
return 0;
}
第9题:
有如下程序: #include<iostream.h> using namespace std; Class Base { public: Base(){cout<<“BB”;f();} void{(){cout<<“BF”;} }; class Derived:public Base { public: Derived(){cout<<“DD”;} void f(){cout<<“Df”;) }; int main
A.BBBfDD
B.BBDfDDDf
C.DD
D.DDBBBf