大小端判断

#include <iostream>#include <stdio.h>using namespace std;int main(){  //小端 数据高字节保存在内存高地址，地址由大向小增长  //对以下两种方法，小端输出4 3 2 1  //方法1  union {    int i;    char c[sizeof(int)];  }un;  un.i = 0x01020304;  cout << (int)un.c[0] << "\t" << (int)un.c[1] << "\t" << (int)un.c[2] << "\t" << (int)un.c[3] << endl;  //方法2  int a = 0x01020304;  char p = ((char *) &a)[0];  char q = ((char *) &a)[1];  char r = ((char *) &a)[2];  char s = ((char *) &a)[3];  cout << (int)p << "\t" << (int)q << "\t" << (int)r << "\t" << (int)s << endl;  int ttt = 0;  return 0;}