國立暨南國際大學 96 學年度第二學期小考試卷

(考試時間: 8:10-8:25)
Open book; turn off computer & mobile phone

1. (10%) Determine whether the following code is correct or not.  If it is correct, predict its output.  If it is incorrect, point out the mistake(s).
   

   #include <iostream>
   using std::cout;
   using std::endl;
   
   class CBox
   {
   public:
   	CBox(double lv=1.0, double wv=1.0, double hv=1.0) 
   		:m_Length(lv), m_Width(wv), m_Height(hv)
   	{ 	}
   
   protected:
   	double m_Length;
   	double m_Width;
   	double m_Height;
   };
   
   int main()
   {
   	CBox myBox(1, 2, 3);
   	cout << myBox.m_Height << endl;	
   }
   
   
   
      

2. (10%) Determine whether the following code is correct or not.  If it is correct, predict its output.  If it is incorrect, point out the mistake(s).

   
   #include <iostream>
   using std::cout;
   using std::endl;
   
   class CBox
   {
   public:
   	CBox(double lv=1.0, double wv=1.0, double hv=1.0) 
   		:m_Length(lv), m_Width(wv), m_Height(hv)
   	{ // cout << endl << "CBox constructor called"; 
   	}
   	
   	~CBox() {  cout << "CBox destructor called" << endl; 
   	}
   
   protected:
   	double m_Length;
   	double m_Width;
   	double m_Height;
   
   friend int main();
   };
   
   class CCandyBox: public CBox
   {
   public: 
   	char* m_Contents;
   	CCandyBox(double lv, double wv, double hv, char* str = "Candy")
   		:CBox(lv, wv, hv)
   	{
   		// cout << endl << "CCandyBox constructor called";
   		m_Contents = new char [ strlen(str) + 1 ];
   		strcpy_s(m_Contents, strlen(str) + 1, str);
   	}
   
   	~CCandyBox()
   	{
   		cout << "CCandyBox destructor called" << endl;
   	}
   };
   
   int main()
   {
   	CCandyBox myToffeeBox(2, 3, 4, "Stickjaw Toffee");	 
   	CCandyBox* p2 = &myToffeeBox;
   	CBox* p1 = dynamic_cast<CBox*>(p2);	
   	cout << p1->m_Length << endl;		
   }