مطالعه موردی کلاسها: آرایه پویا

 
typedef unsigned char byte;
class SmartArray{
public:
   //Default constructor
   SmartArray(){
      init();
   };
   //Another constructor
   SmartArray(int length, bool initialize = false, byte initVal = 0)
   {
      init(length, initialize, initVal);
   };
   //A member function to initialize array
   bool init(int length = 0, bool initialize = false, byte initVal = 0){
      assert(length >= 0);
      if(length <= 0){
         this->length = 0;
         pData = NULL;
         return true;
      }
      this->length = length;
      pData = new byte[length];
      if(initialize){
         for (int i = 0; i < length; i++)
            pData[i] = initVal;
      }
      return true;
   };
   //The only destructor
   ~SmartArray()
   {
      if(pData){
         length = 0;
         delete [] pData;
         pData = NULL;
      }
   };
   //A member function to access array elements
   byte get(int i){
      assert(pData);
      assert(length > i && i > -1);
      if(!pData || length <= i || i < 0)
         return 0;
      return pData[i];
   }
   //A member function to change array elements
   bool set(int i, byte b)
   {
      assert(pData);
      assert(length > i && i > -1);
      if(!pData || length <= i || i < 0)
         return false;
      pData[i] = b;
      return true;
   }
 
   bool RandomFill()
   {
      srand(time(0));
      for(int i = 0; i < length; i++)
         pData[i] = rand() % 256;
      return true;
   }
   void print(int idx0 = 0, int idx1 = -1)
   {
      idx0 = max(0, idx0);
      idx1 = min(length-1, idx1);
      if(idx1 < 0)
         idx1 = length-1;
      printf("The array contains:\n");
      for (int i = idx0; i <= idx1; ++i)
      {
         printf("[%d]: %.3d\n", i, pData[i]);
      }
   }
private:
   byte* pData;
   int length;
};