下列程序的执行结果是 ( ) public class ex68{ public static void main(String[]args){ ex68 obj=new ex68(); int s=0; for(int i=1;i<=4;i++){ s+=obj.method(i); } System.out.println(s); } public int method(int n){ if(n==1) return 1; else return n*method(n-1); } }
A.3
B.9
C.33
D.153
第1题:
下列程序的运行结果是______。
include<iostream.h>
class A
{
public:
virtual void use( ) {cout<<"in A\n";}
};
class B:public A
{
public:
virtual void use( ) {cout<<"in B\n";}
};
class C:public B
{
public:
virtual void use( ){cout<<"in C\n";}
};
void main( )
{
A*obj;
bj=new C;
obj->use( );
delete obj;
}
第2题:
以下程序的执行结果是______。
include<iostream.h>
class base
{
public:
virtual void who(){cout<<"base class"<<endl:}
};
class derrvel:public base
{
public:
void who(){cout<<"derivel class"<<endl:}
};
class derive2;public base
{
public:
void who() {cout<<"derive2 class"<<endl;}
};
void main()
{
base obj1,*P;
derive1 obj2;
derive2 obj3:
p=&obj1;
p->who();
p=&obj2:
p->who();
p=&obj3;
p->who();
}
第3题:
下列程序执行结果是 #include <iostream.h> class A { public: int a; A():a(10){cout<<a<<endl;} }; void main() { A obj1; A obj2(obj1); cout<<" "<<obj2.a<<endl; }
A.10 10
B.编译错误缺少拷贝构造函数
C.10随机数
D.随机数随机数
第4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5题:
有以下程序: #include <iostream> using namespace std; class Base { public: Base(){} virtual void who() { cout<<"Base Class"<<end1; } ~Base(){} }; class Derivel : public Base { public: void who() { cout<<"Derivel Class"<<end1; } }; class Derive2 : public Base { public: void who () { cout<<"Derive2 Class"<<end1; } }; int main () { Base *p; Derivel obj1; Derive2 obj2; p=&obj1; p=&obj2; p->who ( ); return 0; } 执行程序后的输出结果是( )。
A.Base Class
B.Derivel Class
C.Derive2 Class
D.程序编译时出错
第6题: