Mid-Term Exam (1)
C++ Programming
NCNU CSIE

Date: March 3rd, 2010
Time: 14:10-16:00
Open book; turn off computer & mobile phone

1. (20%) 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;
   
   class CStack
   {
   public:
           CStack()        // Default Constructor
           {
                   index = 0;
           }
           void push(int i)
           {
                   a[index++] = i;
           }
           int pop()
           {
                   return a[--index];
           }
   private:
           #define         StackSize       10
           int a[StackSize];
           int index;
   };
   
   int main() {
     CStack stack1;
     stack1.push(3); stack1.push(8);
     stack1.pop();
     cout << stack1.pop() << "\n";
   }
   

2. (20%) 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;
   
   float average(float a, float b);
   float average(float a, float b, float c);       // overloading
   
   int main()
   {
       cout << average(1.0, 4.0, 7.0) << "\n";
       cout << average(1,0, 5.0) << "\n";
       return 0;
   }
   
   float average(float a, float b)
   { return (a+b)/2.0; }
   
   float average(float a, float b, float c)
   { return (a+b+c)/3.0; }
   
   
   
3. (20%) 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;
   
   void test(int& i)
   { cout << i << "\n"; }
   
   int main()
   {
       int n = 33;
       test(n);            // pass-by-value or pass-by-reference?
       return 0;
   }
   
   
   
4. (20%) 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;
   
   int main()
   {
       int i, n = 33;
       for (i=1; i<6; i++)
       {
           int n = 0;
           for (int j=1; j<=i; j++)
               n += j;			// scope of variable n
           cout << n << "\n";
       }
       return 0;
   }

5. (20%) 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> // Ex7_06.cpp
   using std::cout;
   using std::endl;
   
   class CBox // Class definition at global scope
   {
   public:
   double m_Length; // Length of a box in inches
   double m_Width; // Width of a box in inches
   double m_Height; // Height of a box in inches
   
   // Constructor definition
   CBox(double lv = 1.0, double bv = 2.0, double hv = 3.0)
   : m_Length(lv), m_Width(bv), m_Height(hv) // Initialization list
   {
   cout << endl << "Constructor called.";
   }
   
   // Function to calculate the volume of a box
   double Volume()
   {
   return m_Length*m_Width*m_Height;
   }
   };
   
   int main()
   {
   CBox box1; // Declare box1 - no initial values
   CBox box2 = box1; // Default Copy Constructor
   
   cout << endl
   << "Volume of box2 = "
   << box2.Volume();
   
   cout << endl;
   return 0;
   }