1)、const在前面 

  const int nValue; //nValue是const 

  const char *pContent; //*pContent是const, pContent可变 

  const (char *) pContent;//pContent是const,*pContent可变 

  char* const pContent; //pContent是const,*pContent可变 

  const char* const pContent; //pContent和*pContent都是const 

  2)、const在后面,与上面的声明对等 

  int const nValue; // nValue是const 

  char const * pContent;// *pContent是const, pContent可变 

  (char *) const pContent;//pContent是const,*pContent可变 

  char* const pContent;// pContent是const,*pContent可变 

  char const* const pContent;// pContent和*pContent都是const