请教一个数据存储的高低地址问题

typedef struct tag_PLAYER

{

unsigned char bFlag;

unsigned short sSum;

union

  {

   unsigned char strName[3];

   unsigned long IPlayerId;

   unsigned short sGroupId;

   };

unsigned short sAction;

unsigned long IParam;

} P;AYER,* PPLAYER;

VOID main()

{

 PLAYER m;

 m.bFlag=255;

 m.sSUM=0×0102;

m.IPlayerId=0x002233ff;

m.sAction=4;

m.lParam=0×10203040;

printf(“size=%d\n”,sizeof(m);

printf(“PlayerId=0x%x\n”,m.sGruopId);

printf(“Name[[0]=%u;Name[3]=%u\n”,m.strName[0],m.strName[3]);

unsigned short * p =&m.sGroupId;

p+=4;

printf(“*p=0x%x”,*p);

}

 

参考答案:size=16

playerId=0X33FF

nAME[0]=255;Name[3]=0

*p=0×3040;

问题一:32 位机器中long int 为4字节??

问题二:共用体(联合体)中,如本例中

union

  {

   unsigned char strName[3];

   unsigned long IPlayerId;

   unsigned short sGroupId;

   };

m.IPlayerId=0x002233ff;

给long int 的IPlayerId赋值后,sGroupId取他的低位??

问题三:机器是怎样存储数据的?低位存在低地址,还是存高地址?

从本例中来看:低位存在高地址中.