c语言_测试大小端

大端：高字节在前，或者高位字节存储在低位端，0x1234,0x12存储在数组的前面；

小端：低字节在前，或者高位字节存储在高位端，0x1234,0x12存储在数组的后面，后面为高位端 

#include<iostream>
using namespace std;
typedef union test
{
	unsigned int intPort;
	unsigned char charPort;
	struct 
	{
		unsigned int bit0 : 1;
	    unsigned int bit1 : 1;
		unsigned int bit2 : 1;
		unsigned int bit3 : 1;
		unsigned int bit4 : 1;
		unsigned int bit5 : 1;
		unsigned int bit6 : 1;
		unsigned int bit7 : 1;

	}bits;
};

int main()
{
	test aa;
	aa.intPort = 1;
	cout << aa.bits.bit0 << endl;
	if(aa.bits.bit0 == 0x01)
	{
		cout <<"系统为小端"<< endl;
	}
	else {
		cout << "系统为大端" << endl;
	}
	if (aa.charPort == 0x01)
	{
		cout << "系统为小端" << endl;
	}
	else {
		cout << "系统为大端" << endl;
	}
}