C++中纯虚函数的实例详解

class Base
{
public:
    virtual void Examp() = 0;//纯虚函数
    ~Base()
    {
        cout << "父类的析构函数" << endl;
    }
};
 
class Son:public Base
{
public:
    void Examp()
    {
        cout << "重写了父类的纯虚函数" << endl;
    }
    
    ~Son()
    {
        cout << "子类的析构函数" << endl;
    }
};
 
int main()
{
    Son p1;
    p1.Examp();
    system("pause");
}

int main()
{
    Son *p1=new Son;//子类对象开辟堆区
    p1->Examp();
    delete p1;//释放堆区，自动调用析构函数
    system("pause");
}

class Base
{
public:
    virtual void Examp() = 0;//纯虚函数
    virtual ~Base()//虚析构
    {
        cout << "父类的析构函数" << endl;
    }
};

class Base
{
public:
    virtual void Examp() = 0;//纯虚函数
 
    virtual ~Base() = 0;//类内声明
};
 
Base::~Base()//类外实现
{
        cout << "父类的析构函数" << endl;
}

include<stdio.h>
#include<iostream>
using namespace std;
class Base
{
public:
        virtual void func()=0;  //在基类中声明纯虚函数
};
class Derived:public Base
{
public:
        void func()         //在子类中重写纯虚函数
        {
                cout<<"哈哈"<<endl;
        }
};
int main()
{
        Base *b=new Derived();      //基类的指针调用子类重写的纯虚函数
        b->func();
        return 0;
}