C++ Primer Plus学习笔记之继承类的初始化顺序

时间：2014-05-04 09:41:27 收藏：0 阅读：373

C++ Primer Plus学习笔记之继承类的初始化顺序

基类的构造函数，析构函数和操作符函数operator=是不能被派生类继承的；

那么，当创建一个派生类对象时，怎样调用基类的构造函数对基类的数据进行初始化呢？？？

答案是：构造函数执行时遵行先兄长(基类)，再客人(对象成员)，后自己(派生类)的顺序；

另一方面，执行析构函数时，先执行派生类的析构函数，再执行基类的析构函数。原因是，对基类的破坏隐含了对派生类的破坏，所以派生类的析构函数必须先执行；

#include<iostream>

using namespace std;

class Member
{
	public:
		Member()
		{
			cout<<"Member created"<<endl;
		}
		~Member()
		{
			cout<<"Member destroyed"<<endl;
		}
};

class Base
{
	public:
		Base()
		{
			cout<<"Base created"<<endl;
		}
		~Base()
		{
			cout<<"Base destroyed"<<endl;
		}
};

class Derived:public Base
{
	public:
		Derived()
		{
			cout<<"Derived created"<<endl;
		}
		~Derived()
		{
			cout<<"Derived destroyed"<<endl;
		}
	private:
		Member m;
};

int main(int argc,char *argv[])
{
	Derived d;

	return 0;
}

运行结果：

Base created

Member created

Derived created

Derived destroyed

Member destroyed

Base destroyed

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