C++ virtual descructor

最新推荐文章于 2024-04-09 16:53:11 发布

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最新推荐文章于 2024-04-09 16:53:11 发布

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原文链接：http://www.cnblogs.com/hellogiser/p/cplusplus-virtual-destructor.html

【代码1】

 C++ Code 

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/*
    version: 1.0
    author: hellogiser
    blog: http://www.cnblogs.com/hellogiser
    date: 2014/9/22
*/

#include "stdafx.h"
#include "iostream"
#include <assert.h>
using namespace std;

void print(const char *str)
{
    cout << str << endl;
}

class A
{
public:
    A()
    {
        p();
    }
    virtual void p()
    {
        print("A");
    }
    virtual ~A()
    {
        p();
    }
};

class B: public A
{
public:
    B()
    {
        p();
    }
    void p()
    {
        print("B");
    }
    ~B()
    {
        p();
    }
};

int main(int, char **)
{
    A *a = new B();
    delete a;
}

/*
A
B
B
A
*/

如果A类的析构函数去掉virtual呢？

【代码2】

 C++ Code 

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/*
    version: 1.0
    author: hellogiser
    blog: http://www.cnblogs.com/hellogiser
    date: 2014/9/22
*/

#include "stdafx.h"
#include "iostream"
#include <assert.h>
using namespace std;

void print(const char *str)
{
    cout << str << endl;
}

class A
{
public:
    A()
    {
        p();
    }
    virtual void p()
    {
        print("A");
    }
    ~A()
    {
        p();   // remove virtual
    }
};

class B: public A
{
public:
    B()
    {
        p();
    }
    void p()
    {
        print("B");
    }
    ~B()
    {
        p();
    }
};

int main(int, char **)
{
    A *a = new B();
    delete a;
}

/*
A
B
A
*/

转载于:https://www.cnblogs.com/hellogiser/p/cplusplus-virtual-destructor.html