C++ 虚析构函数的作用

来源：互联网发布：美国护理学硕士知乎编辑：程序博客网时间：2024/06/15 07:05

一，如果析构函数不是虚的，则只将调用对应于指针类型的析构函数

#include <iostream>using namespace std;class People{public:    ~People(){        cout<<"People Object Delete."<<endl;    }};class Student : public People{    ~Student(){        cout<<"Student Object Delete."<<endl;    };};int main(){    People *p = new Student;    delete p;    return 0;}

输出结果：

People Object Delete.Process returned 0 (0x0)   execution time : 0.012 sPress any key to continue.

二，如果析构函数是虚的，将调用实际指向的对象的析构函数

如果指针指向的是派生类的对象，将调用派生类对象的析构函数，然后再调用基类对象的析构函数。因此，使用虚析构函数可以确保正确的析构函数调用顺序。

#include <iostream>using namespace std;class People{public:    //把基类的析构函数声明为虚的   virtual ~People(){        cout<<"People Object Delete."<<endl;    }};class Student : public People{    ~Student(){        cout<<"Student Object Delete."<<endl;    };};int main(){    People *p = new Student;    delete p;    return 0;}

输出结果：

Student Object Delete.People Object Delete.Process returned 0 (0x0)   execution time : 0.020 sPress any key to continue.

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