析构函数虚函数

#include<iostream>
#include<list>
#include<string>
#include<vector>
using namespace std;

class base
{
public:
	~base()
	{
		cout<<"父类析构函数被调用"<<endl;
	}
};

class derived:public base
{
public:
	char *m_str;
	derived()
	{
		m_str = new char(100);
	}
	~derived()
	{
		cout<<"子类的析构函数被调用"<<endl;
		delete m_str;
	}
};

int main()
{
/*******就是为了处理这种父类指针指向子类对象的情况，使用了虚函数析构*********/
	base *p = new derived();//父类指针指向子类对象
	delete p ;//这是只调用了父类的析构函数，未执行子类的析构函数delete m_str;造成内存泄漏

	base *m = new base();//父类指针指向父类
	delete m;//这是不会造成内存泄漏

  derived* q = new derived();//子类指针指向子类对象
  delete q;//不会造成内存泄漏，先调用自身析构，再调用父类析构
  return 0;
}

输出：
父类析构函数被调用
父类析构函数被调用
请按任意键继续. . .