c++与c中动态内存分配的比较

  C语言： malloc/calloc/realloc  free()
  C++: new/delete 运算符
  new运算符用于动态内存分配，delete运算符用于动态内存释放
  eg:
  C:
    int *p = (int *)malloc(sizeof(int));
    *p = 100;
    free(p);
    p = NULL;
 C++:
   //int *p = new int;
   //*p = 100;
   int *p = new int(100);
   delete p;
   p = NULL;
   int *parr = new int[10];
   parr[0] = 10;
   parr[1] = 20;
   *(parr + 2) = 30;
   ...
   delete[]  parr;
   parr = NULL;