#include "stdafx.h"
#include<iostream>
using namespace std;
struct A
{
 int a;
 int b;
 int c;
};

struct B
{

};

struct C
{
 char a;
 int i;
} ;

struct D
{
 int i;
 char a;
};

struct E
{
 char a;
};

int _tmain(int argc, _TCHAR* argv[])
{
 cout<<sizeof(A)<<endl;

 cout<<sizeof(B)<<endl;

 cout<<sizeof(C)<<endl;

 cout<<sizeof(D)<<endl;

 cout<<sizeof(E)<<endl;

 getchar();

 return 0;
}

运行结果是 12
                     1
                     8
                     8
                     1
A好理解，3个int，每个4个字节，正好12个