國立暨南國際大學 99 學年度第二學期小考試卷

(考試時間: 10:30-10:45)

1. (10%) Determine whether the following code has syntax erros or not.  If it is correct, predict its output.  If it is
   incorrect, point out the mistake(s).
   
   #include <iostream>          // Ex8_02.cpp
   #include <cstring>           // For strlen() and strcpy()
   using std::cout;
   using std::endl;
   
   class CMessage
   {
     private:
       char* pmessage;                   // Pointer to object text string
   
   
     public:
   	static int objectCount;
       // Constructor definition
   	 CMessage(const char* text = "Default message")
       {
         pmessage = new char[strlen(text) + 1];   // Allocate space for text
         strcpy(pmessage, text);                  // Copy text to new memory
   	  cout << objectCount << " : " << pmessage << endl;
   	  objectCount++;
       }
   
       ~CMessage()                               
   	{  delete[] pmessage; }
   };
   
   int CMessage::objectCount = 0;
   
   void f1()
   {
   	CMessage msg1("Sunday");
   	CMessage msg2("Monday");
   }
   
   void f2()
   {
   	CMessage msg2("Tuesday");
   	CMessage msg3("Wednesday");
   }
   
   int main()
   {
     f1();	f2();
      return 0;
   }
   
   

2. (10%) Determine whether the following code has syntax erros 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 CRational 
   {
     public:
       int* pnumerator;		// 分子
   	int* pdenominator;	// 分母
   
   	CRational(int a=0, int b=1)		
   	{
   		pnumerator = new int;
   		*pnumerator = a;
   		pdenominator = new int;
   		*pdenominator = b;
   
   		if (b==0)
   		{
   			cout << "Error! The denominator cannot be 0.\n";
   			exit(1);
   		}
   	}
   
   	void Print()
   	{
   		cout << *pnumerator;
   		if (*pdenominator != 1)
   			cout << "/" << *pdenominator;
   		cout << endl;
   	}
   };
      
   int main()
   {
     CRational x(1,3);
     CRational y(x);
     *(y.pdenominator) = 5;
     x.Print(); y.Print();
     return 0;
   }