[C++知识库]C++纯虚函数及纯虚类

基类中的纯虚类成员函数需要在派生类中实现其定义，

#include <iostream>

using namespace std;

class myBase
{
private:
    /* data */
    int m_id;
    int m_width;
    int m_height;
public:
    myBase(/* args */);
    ~myBase();

    int firstFunction();
    virtual int onConnect() = 0;
    virtual int onDataIn() = 0;
};

myBase::myBase(/* args */)
{
    printf("construct myBase obj\n");
}

myBase::~myBase()
{
    printf("destory myBase obj\n");
}

class myPeople: public myBase
{
private:
    /* data */
public:
    myPeople(/* args */);
    ~myPeople();    
    
    virtual int onConnect();
    virtual int onDataIn();
};

myPeople::myPeople(/* args */)
{
    printf("construct myPeople obj\n");
}

myPeople::~myPeople()
{
    printf("destory myPeople obj\n");
}

int myPeople::onConnect()
{
    printf("onConnect comming\n");
}

int myPeople::onDataIn()
{
    printf("onDataIn comming\n");
}

int main()
{
    myPeople *pobj = new myPeople;
    
    cout << "pobj" << pobj << endl;
    
    delete pobj;
    
    printf("[%s|%d] main exit\n", __FUNCTION__, __LINE__);
    return 0;
}