C++ :继承下的构造函数和析构函数执行顺序

构造顺序

继承下，构造顺序前后顺序为：基类 ， 内嵌子对象（成员类），派生类
其中，内嵌子对象，按照声明顺序，基类按照继承的先后顺序

析构顺序

与构造顺序相反

code

父类 子类

#include <iostream>

using namespace std;

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

};

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

};


int main()
{
    Drive d;
    return 0;
}

运行结果：
Base
Drive
~Drive
~Base

父类 子类 派生类

#include <iostream>

using namespace std;

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

};

class Base1
{
public:
    Base1()
    {
        cout<<"Base1"<<endl;
    }
    ~Base1()
    {
        cout<<"~Base1"<<endl;
    }

};
class Drive : public Base
{
public:
    Drive()
    {
        cout<<"Drive"<<endl;
    }
    ~Drive()
    {
        cout<<"~Drive"<<endl;
    }
private:
    Base1 b1;
};


int main()
{
    Drive d;
    return 0;
}

运行结果：
Base
Base1
Drive
~Drive
~Base1
~Base

多继承

#include <iostream>

using namespace std;


class Base1
{
public:
    Base1()
    {
        cout<<"Base1"<<endl;
    }
    ~Base1()
    {
        cout<<"~Base1"<<endl;
    }

};

class Base2
{
public:
    Base2()
    {
        cout<<"Base2"<<endl;
    }
    ~Base2()
    {
        cout<<"~Base2"<<endl;
    }

};

class MBase1
{
public:
    MBase1()
    {
        cout<<"MBase1"<<endl;
    }
    ~MBase1()
    {
        cout<<"~MBase1"<<endl;
    }

};

class MBase2
{
public:
    MBase2()
    {
        cout<<"MBase2"<<endl;
    }
    ~MBase2()
    {
        cout<<"~MBase2"<<endl;
    }

};


class Drive : public MBase1, public MBase2
{
public:
    Drive()
    {
        cout<<"Drive"<<endl;
    }
    ~Drive()
    {
        cout<<"~Drive"<<endl;
    }
private:
    Base1 b1;
    Base2 b2;

};


int main()
{
    Drive d;
    return 0;
}

运行结果：
MBase1
MBase2
Base1
Base2
Drive
~Drive
~Base2
~Base1
~MBase2
~MBase1