脚本执行失败问题
1. 虚函数是可以内联的，这样就可以减少函数调用的开销，提高效率（错误）
2. 一个类里可以同时存在参数和函数名都相同的虚函数与静态函数（错误）
3. 父类的析构函数是非虚的，但是子类的析构函数是虚的，delete子类指针(指向该子类对象)，会调用父类的析构函数（正确）//任何情况下删除子类都会调用到父类的析构函数
4．对于下面的类CA，sizeof(CA) = _B_：
A. 4 B. 8 C. 12 D. 16
class CA
{
public:
CA();
virtual ~CA(); //因为有虚函数，所以会有4个字节的虚表指针
private:
int m_iTime; //成员变量4个字节
public:
int GetTime();
int SetTime(int iTime);
};
5．下面这段程序，打印结果是_A_：
A. 1 B. 2 C. 3 D. 以上都不对
int g_iCount = 0;
class CParent
namespace是干嘛的
{
public:
CParent() {}
~CParent() {g_iCount += 1;}
};
class CSon : public CParent
{
public:
CSon() {}
~CSon() {g_iCount += 2;}
};
main()
{
CParent* p = new CSon();
delete p;
std::cout << g_iCount << std::endl;
}
6．请问下面这段程序的输出结果是_A_：
A. 2,1, B. 2,2, C. 1,1, D. 1,2,
class CParent
{
public:
CParent() {}
virtual ~CParent() {}
public:
virtual void Print()
{ std::cout << "1,"; };
};
class CSon : public CParent
{
public:
CSon() {};
virtual ~CSon() {};
public:
void Print()
{ std::cout << "2,"; };
};
void Test1(CParent& oParent)
{oParent.Print();}
void Test2(CParent oParent)
{oParent.Print();}
main()
{
CSon * p = new CSon();
Test1(*p); //这里只是一个引用
Test2(*p); //这里会在栈空间重新构造Cparent类对象
delete p;
}
7．请问下面这段程序的输出结果是_D_：
A. 2,1, B. 2,2, C. 1,1, D. 1,2,
class CParent
{
public:
CParent() {}
virtual ~CParent() {}
public:
void Print(){ std::cout << "1," ; };
};
class CSon : public CParent
{
public:
CSon() {}
virtual ~CSon() {}
public:
void Print(){ std::cout << "2,"; };
};
main()
{
CSon oSon;
CParent * pParent = &oSon;
CSon * pSon = &oSon;
pParent->Print();
pSon->Print();
}
8．请问下面这段程序的输出结果是_C_：
A. 2,1, B. 2,2, C. 1,2, D. 1,1,
class CParent
{
public:
CParent() {Print();}
virtual ~CParent() {}
public:
virtual void Print(){ std::cout << "1,"; }
};
class CSon : public CParent
{
public:
CSon() {Print();}
virtual ~CSon() {}
public:
void Print(){ std::cout << "2,"; }
};
main()
{
CParent * pParent = new CSon();
delete pParent;
}
9．请问下面这段程序的输出结果是_D_：
A. 2,2, B. 2, C. 输出结果不确定 D. 以上都不对
class CParent
{
public:
CParent() {Print();}
virtual ~CParent() {}
public:
virtual void Print() = 0;
};
class CSon : public CParent
{
public:
CSon() {Print();}
virtual ~CSon() {}
public:
void Print()
{ std::cout << "2,"; };
};
main()
{
CParent * pParent = new CSon();
delete pParent;
}
10．请仔细阅读以下程序：
class Base
{
public:
virtual bool operator == (int iValue)
{
std::cout << "I am Base class !" << std::endl;
return true;
}
virtual ~Base(){}
};
class Derive: public Base
{
public:
virtual bool operator == (int iValue)
{
std::cout << "I am Derive class !" << std::endl;
return true;
}
virtual ~Derive(){}
};
int main()
{
Derive derive;
Base* pBase = &derive;
Derive* pDerive = &derive;
*pBase == 0;
*pDerive == 0;
return 0;
}
程序的输出结果是_B_：
A、I am Base class !
I am base class !
B、I am Derive class !
I am Derive class !
C、I am base class !
I am Derive class !
D、I am Derive class !
I am Base class !
11．请仔细阅读以下程序：
class Base
{
public:
virtual void display(std::string strShow = "I am Base class !")
{ std::cout << strShow << std::endl; }
virtual ~Base(){}
};
class Derive: public Base
{
public:
virtual void display(std::string strShow = "I am Derive class !")
{ std::cout << strShow << std::endl; }
virtual ~Derive(){}
};
int main()
{
Base* pBase = new Derive();
Derive* pDerive = new Derive();
pBase->display();
pDerive->display();
delete pBase;
delete pDerive;
return 0;
}
程序的输出结果是_C_：
A、I am Base class !
I am base class !
B、I am Derive class !
I am Derive class !
C、I am base class !
I am Derive class !
D、I am Derive class !
I am Base class !
12．请仔细阅读以下程序：
class Base
{
public:
virtual void display() const
{ std::cout << "I am Base class !" << std::endl; }
virtual ~Base(){}
};
class Derive: public Base
{
public:
virtual void display()
{ std::cout << "I am Derive class !"<< std::endl; }
virtual ~Derive(){}
};
int main()
{
Base* pBase = new Derive();
Derive* pDerive = new Derive();
pBase->display();
pDerive->display();
delete pBase;
delete pDerive;
return 0;
}
程序的输出结果是_C_：
A、I am Base class !
I am base class !
B、I am Derive class !
I am Derive class !
C、I am base class !
I am Derive class !
D、I am Derive class !
版权声明：本站内容均来自互联网，仅供演示用，请勿用于商业和其他非法用途。如果侵犯了您的权益请与我们联系QQ:729038198，我们将在24小时内删除。
发表评论