/***A.h文件***/
#pragma once
class A
{
public:int va;A(void);A(char* name);A(const A& a);virtual void print();char* name;void setVa(int va){this->va = va;}
public:~A(void);
};

/****A.cpp文件******/
#include "StdAfx.h"
#include "A.h"
#include <iostream>using namespace std;A::A(void)
{
cout<< "a constructor is invoked .." << endl;
this->va = 5;
}A::A(char* name)
{
this->name = name;
cout<< "constructor of object of Class A, whose name is " << name << " , is invoked .." << endl;
}A::~A(void)
{
cout<< "a[name is "<< name <<"] is destroy .." << endl;}A::A(const A& a){
//cout<< "a[name="<< this->name <<"] copy constructor is invoked.." << endl;
cout<< "A copy constructor is invoked.." << endl;
this->name = a.name;
this->va = a.va;
}void A::print(){
cout << "this is a" << endl;
}

#pragma once
#include "a.h"class B :public A
{public:int va;//在这里重新声明了va变量B(char* name4A);void print();static int i;
public:~B(void);
};

#include "StdAfx.h"
#include "B.h"
#include <iostream>
using namespace std;B::B(char * name4A):A(name4A)
{this->setVa(10);cout<< "b constructor is invoked .." << endl;this->va = 3;
}B::~B(void)
{cout<< "b is destroy .." << endl;
}void B::print(){cout << "this is B" << endl;
}int B::i = -1;

// cplusplusprimer.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include "A.h"
#include "B.h"
#include <iostream>
using namespace std;static int i;
int j ;int _tmain(int argc, _TCHAR* argv[])
{A a("aSelf");B b("aFromB");//A a1("aSelf1");
    cout<<"Hello C-Free!"<<endl;a.va = -1;b.va = -2;//a1.va = -3;
     cout<< "a.va=" <<a.va<<endl;cout<< "b.va=" <<b.va<<endl;cout<< "*************************************"  <<endl;a= b;a.name = "aSelf";//下面的这条命令//在这里你认为输出的值应该是什么呢//你是不是认为输出的应该是-2,但事实上呢输出的是10,为什么呢?(问题1)cout<<"a.va="<<a.va<<endl;cout<<"b.va="<<b.va<<endl; a.print();cout<< "*************************************"  <<endl;/************************************************************************//* 一般来说，变量(不管是普通变量，还是类成员变量)都需要初始化的，如果没初始化就使用了，可能会出现未知的错误/************************************************************************/cout<<"i="<<i<<endl;//静态变量系统会分配一个默认值给他cout<<"j="<<j<<endl;/*int q;cout<<"j="<<q<<endl;//因为没有进行初始化，所以这里出错了 */cout<<"b.i="<<b.i<<endl; a.print();return 0;
}