测试系统的大小印第安序

直接贴代码了：

#include <stdio.h>

typedef unsigned char BYTE;

int main(void) {

unsigned int num, *p;

p=#

num=0;

*(BYTE *)p=0xff;

if(num==0xff){

printf("its little");

}

else{

printf("its big");

}

return 0;

}

一般X86，ARM是小。

num

is
an

unsigned
 int

p

is
a pointer to that same int.

(BYTE*)p

means "pretend
its really a pointer to a byte instead".

*(BYTE*)p
 =

means "Go set that byte to be the value on the RHS."

the value on the RHS is

0xFF

.

Result: num is a 4-byte integer.

One byte of that int will be set to

0xFF

(it could be the high-byte or the low-byte depending on your platform)

So

num

will
either end up being

0xFF
 00 00 00

, or possibly

0x00
 00 00 FF