國立暨南國際大學 101 學年度第一學期小考試卷

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).
   
   // Pointers as Arguments to a Function
   #include <iostream>
   
   int strlen(char* s)
   {
       char* p = s;
       while (*s != '\0')
           ++s;
       return s - p;
   }
   
   int main()
   {
       char* str = "NCNU";
       int n = strlen(str);
       printf("The length of \"%s\" is %d.\n",
           str, n);
       return 0;
   }
   
   
   
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).
   
   // Pass-by-reference
   #include <iostream>
   
   int strlen(char* &s)
   {
       char* p = s;
       while (*s != '\0')
           ++s;
       return s - p;
   }
   
   int main()
   {
       char* str = "NCNU";
       int n = strlen(str);
       printf("The length of \"%s\" is %d.\n",
           str, n);
       return 0;
   }
   
   
   
3. (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).
   // Static variable
   #include <iostream>
   
   int CountDown()
   {
       static int n = 10;
       // Try this code with static and try it without it
       if (n>0)
           return n--;
       else
           return 0;
   }
   
   int main()
   {
       CountDown();
       CountDown();
       std::cout << CountDown() << std::endl;
       return 0;
   }