virtual析构函数

Published: 05 Dec 2015 Category: c++

一、文章来由

同样项目中是遇到这个问题~~

二、直接上代码来的清楚

#include <iostream>
using namespace std;

class Father
{
public:
    Father() {
        cout<<"父类诞生了"<<endl;
    }

    ~Father() {
        cout<<"父类挂了"<<endl;
    }

protected:
private:
};

class Kid : public Father
{
public:
    Kid() {
        cout<<"子类诞生了"<<endl;
    }

    ~Kid() {
        cout<<"子类挂了"<<endl;
    }

protected:
private:
};

int main() 
{
    Father *f = new Kid();
    delete f; //只delete父类,子类不会被析构

    cout<<endl;

    Father *f1 = new Kid();
    delete (Kid *)f1;

    return 0; 
}

这样在调用父类析构函数时,并不会析构子类,于是运行结果如下:

这里写图片描述

但是如果让父类的析构函数是virtual的,就可以正常析构子类,可见多态在c++里面有多强大~~

    virtual ~Father() {
        cout<<"父类挂了"<<endl;
    }

这里写图片描述

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