大小端

大端

• 低地址存高位

小端

• 低地址存低位

测试

测试自己电脑大小端

#include <stdio.h>

//我的是小端
int main() {

    // 1027 = 1024 + 3 = 0x403 = 0100 0000 0003 (2)
    int a = (1 << 1) + (1 << 10) + (1 << 20) + (1 << 30); //4字节
    a = 1027;
    printf("%d\n", a);
    printf("%#x\n", a); 
    
    //因为int四字节
    char *p = (char*)&a;
    
    printf("address: %p, value: %#x\n", p, *p);
    printf("address: %p, value: %#x\n", p + 1, *(p + 1));
    printf("address: %p, value: %#x\n", p + 2, *(p + 2));
    printf("address: %p, value: %#x\n", p + 3, *(p + 3));


    return 0;
}

十进制	二进制	十六进制
1027	0100 0000 0003	0x403

输出结果

小端

1027
0x403
address: 0x7fff190f3a4c, value: 0x3
address: 0x7fff190f3a4d, value: 0x4
address: 0x7fff190f3a4e, value: 0
address: 0x7fff190f3a4f, value: 0