C++面向对象入门(三十)继承构造函数和析构函数

C++继承中的构造和析构
C++派生类能继承大多数基类的成员, 但不包括构造函数(包括拷贝函数), 析构函数

C++继承中构造函数的调用顺序(单继承)
1 调用基类的构造函数, 初始化基类成员, 如果基类也是派生类, 则递归调用基类的基类的构造函数
2 调用自身的构造函数, 初始化成员

C++继承中的析构函数调用顺序
1 派生类自身析构函数
2 派生类子对象成员的析构函数(如果有子对象)
3 普通基类的析构函数
4 虚基类的析构函数

 

继承关系图:

 

 

 

代码示例:

#include <iostream>
#include "No47_singleInheritanceAndConstructorAndDestructor.h"
using namespace std;

/*
C++继承中的构造和析构
C++派生类能继承大多数基类的成员, 但不包括构造函数(包括拷贝函数), 析构函数

C++继承中构造函数的调用顺序(单继承)
1 调用基类的构造函数, 初始化基类成员, 如果基类也是派生类, 则递归调用基类的基类的构造函数
2 调用自身的构造函数, 初始化成员

C++继承中的析构函数调用顺序
1 派生类自身析构函数
2 派生类子对象成员的析构函数(如果有子对象)
3 普通基类的析构函数
4 虚基类的析构函数
*/
class A47 
{
public:
    int a;
    A47();
    ~A47();
};

class B47 
{
public:
    int b;
    B47();
    ~B47();
};

class C47 :public virtual A47, public B47
{
public :
    int c;
    C47();
    ~C47();
};

class D47 :public virtual A47, public B47
{
public:
    int d;
    D47();
    ~D47();
};

class E47
{
public :
    E47();
    ~E47();
    int e;


};

class F47 :public C47, public D47
{
public:
    int f;
    E47 e47;
    F47();
    ~F47();
    void test();
};

void test()
{
    F47 f;
}

int main()
{
    test();
    system("pause");
}


A47::A47():a(1)
{
    cout << "constructor of A47" << endl;
}

A47::~A47()
{
    cout << "destructor of A47" << endl;
}

B47::B47():b(2)
{
    cout << "constructor of B47" << endl;
}

B47::~B47()
{
    cout << "destructor of B47" << endl;
}

C47::C47():A47(),B47(),c(3)
{
    cout << "constructor of C47" << endl;
}

C47::~C47()
{
    cout << "destructor of C47" << endl;
}


D47::D47():A47(),B47(),d(4)
{
    cout << "constructor of D47" << endl;
}

D47::~D47()
{
    cout << "destructor of D47" << endl;
}


E47::E47() :e(5)
{
    cout << "constructor of E47" << endl;
}

E47::~E47()
{
    cout << "destructor of E47" << endl;
}

F47::F47():C47(),D47(),e47(E47()),f(6)
{
    cout << "constructor of F47" << endl;
}

F47::~F47()
{
    cout << "destructor of F47" << endl;
}

void F47::test()
{
    cout << "a = " << a << endl;
    cout << "C47::b = " << C47::b << endl;
    cout << "D47::b = " << D47::b << endl;
    cout << "c = " << c << endl;
    cout << "d = " << d << endl;
    cout << "e = " << e47.e << endl;
    cout << "f = " << f << endl;
}

#include <iostream>
#include "No47_singleInheritanceAndConstructorAndDestructor.h"
using namespace std;

/*
C++继承中的构造和析构
C++派生类能继承大多数基类的成员, 但不包括构造函数(包括拷贝函数), 析构函数

C++继承中构造函数的调用顺序(单继承)
1 调用基类的构造函数, 初始化基类成员, 如果基类也是派生类, 则递归调用基类的基类的构造函数
2 调用自身的构造函数, 初始化成员

C++继承中的析构函数调用顺序
1 派生类自身析构函数
2 派生类子对象成员的析构函数(如果有子对象)
3 普通基类的析构函数
4 虚基类的析构函数
*/
class A47 
{
public:
    int a;
    A47();
    ~A47();
};

class B47 
{
public:
    int b;
    B47();
    ~B47();
};

class C47 :public virtual A47, public B47
{
public :
    int c;
    C47();
    ~C47();
};

class D47 :public virtual A47, public B47
{
public:
    int d;
    D47();
    ~D47();
};

class E47
{
public :
    E47();
    ~E47();
    int e;


};

class F47 :public C47, public D47
{
public:
    int f;
    E47 e47;
    F47();
    ~F47();
    void test();
};

void test()
{
    F47 f;
}

int main()
{
    test();
    system("pause");
}


A47::A47():a(1)
{
    cout << "constructor of A47" << endl;
}

A47::~A47()
{
    cout << "destructor of A47" << endl;
}

B47::B47():b(2)
{
    cout << "constructor of B47" << endl;
}

B47::~B47()
{
    cout << "destructor of B47" << endl;
}

C47::C47():A47(),B47(),c(3)
{
    cout << "constructor of C47" << endl;
}

C47::~C47()
{
    cout << "destructor of C47" << endl;
}


D47::D47():A47(),B47(),d(4)
{
    cout << "constructor of D47" << endl;
}

D47::~D47()
{
    cout << "destructor of D47" << endl;
}


E47::E47() :e(5)
{
    cout << "constructor of E47" << endl;
}

E47::~E47()
{
    cout << "destructor of E47" << endl;
}

F47::F47():C47(),D47(),e47(E47()),f(6)
{
    cout << "constructor of F47" << endl;
}

F47::~F47()
{
    cout << "destructor of F47" << endl;
}

void F47::test()
{
    cout << "a = " << a << endl;
    cout << "C47::b = " << C47::b << endl;
    cout << "D47::b = " << D47::b << endl;
    cout << "c = " << c << endl;
    cout << "d = " << d << endl;
    cout << "e = " << e47.e << endl;
    cout << "f = " << f << endl;
}

#include <iostream>
#include "No47_singleInheritanceAndConstructorAndDestructor.h"
using namespace std;

/*
C++继承中的构造和析构
C++派生类能继承大多数基类的成员, 但不包括构造函数(包括拷贝函数), 析构函数

C++继承中构造函数的调用顺序(单继承)
1 调用基类的构造函数, 初始化基类成员, 如果基类也是派生类, 则递归调用基类的基类的构造函数
2 调用自身的构造函数, 初始化成员

C++继承中的析构函数调用顺序
1 派生类自身析构函数
2 派生类子对象成员的析构函数(如果有子对象)
3 普通基类的析构函数
4 虚基类的析构函数
*/
class A47 
{
public:
    int a;
    A47();
    ~A47();
};

class B47 
{
public:
    int b;
    B47();
    ~B47();
};

class C47 :public virtual A47, public B47
{
public :
    int c;
    C47();
    ~C47();
};

class D47 :public virtual A47, public B47
{
public:
    int d;
    D47();
    ~D47();
};

class E47
{
public :
    E47();
    ~E47();
    int e;


};

class F47 :public C47, public D47
{
public:
    int f;
    E47 e47;
    F47();
    ~F47();
    void test();
};

void test()
{
    F47 f;
}

int main()
{
    test();
    system("pause");
}


A47::A47():a(1)
{
    cout << "constructor of A47" << endl;
}

A47::~A47()
{
    cout << "destructor of A47" << endl;
}

B47::B47():b(2)
{
    cout << "constructor of B47" << endl;
}

B47::~B47()
{
    cout << "destructor of B47" << endl;
}

C47::C47():A47(),B47(),c(3)
{
    cout << "constructor of C47" << endl;
}

C47::~C47()
{
    cout << "destructor of C47" << endl;
}


D47::D47():A47(),B47(),d(4)
{
    cout << "constructor of D47" << endl;
}

D47::~D47()
{
    cout << "destructor of D47" << endl;
}


E47::E47() :e(5)
{
    cout << "constructor of E47" << endl;
}

E47::~E47()
{
    cout << "destructor of E47" << endl;
}

F47::F47():C47(),D47(),e47(E47()),f(6)
{
    cout << "constructor of F47" << endl;
}

F47::~F47()
{
    cout << "destructor of F47" << endl;
}

void F47::test()
{
    cout << "a = " << a << endl;
    cout << "C47::b = " << C47::b << endl;
    cout << "D47::b = " << D47::b << endl;
    cout << "c = " << c << endl;
    cout << "d = " << d << endl;
    cout << "e = " << e47.e << endl;
    cout << "f = " << f << endl;
}

 

运行结果: