高位优先和低位优先

查看内存布局。

可能比较绕口,那就是最低的地址存放高位字节,称为高位优先,最低的地址存放低位字节,成为低位优先

详细的内存察看如下：

代码:

#include  
struct ss{ 
unsigned int i1:1; 
unsigned int i2:1; 
unsigned int i3:1; 
unsigned int i4:1; 
unsigned int i5:1; 
unsigned int i6:1; 
unsigned int i7:1; 
unsigned int i8:1; 
unsigned int j1:1; 
unsigned int j2:1; 
unsigned int j3:1; 
unsigned int j4:1; 
unsigned int j5:1; 
unsigned int j6:1; 
unsigned int j7:1; 
unsigned int j8:1; 
unsigned int k1:1; 
unsigned int k2:1; 
unsigned int k3:1; 
unsigned int k4:1; 
unsigned int k5:1; 
unsigned int k6:1; 
unsigned int k7:1; 
unsigned int k8:1; 
unsigned int l1:1; 
unsigned int l2:1; 
unsigned int l3:1; 
unsigned int l4:1; 
unsigned int l5:1; 
unsigned int l6:1; 
unsigned int l7:1; 
unsigned int l8:1; 
}; 
int main() 
{ 
struct ss s; 
int j=1025; 
memcpy(&s,&j,4); 
printf("%d
",sizeof(struct ss)); 
printf("%d%d%d%d%d%d%d%d
",s.i1,s.i2,s.i3,s.i4,s.i5,s.i6,s.i7,s.i8); 
printf("%d%d%d%d%d%d%d%d
",s.j1,s.j2,s.j3,s.j4,s.j5,s.j6,s.j7,s.j8); 
printf("%d%d%d%d%d%d%d%d
",s.k1,s.k2,s.k3,s.k4,s.k5,s.k6,s.k7,s.k8); 
printf("%d%d%d%d%d%d%d%d
",s.l1,s.l2,s.l3,s.l4,s.l5,s.l6,s.l7,s.l8); 
return 0; 
}

开始说说高位优先和低位优先，我们看如下代码：
int i=10;
那么i在内存中的布局如何哪？
假设内存是从低－－－>高增长的
在低位优先的硬件里面，内存布局如下：
00001010 00000000 00000000 00000000
而在高位优先的内存中：
00000000 00000000 00000000 00001010
这就是我们经常听说的高位优先，低位优先。
那么我们需要注意什么冬冬勒？
看下面一个程序：
#include
    main()
    {
        int a=10;
        short b;
        memcpy(&b,&a,2);
        printf("%d ",b);
    }
如果你输出结果为:10,恭喜你，你的内存存储是低位优先，
如果结果为：0呢？恭喜你，你的内存存储是高位优先。
btw:在处理器中总是高位优先。
 结论: