C++构造函数初始化顺序详解

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

class point
{
private:
    int x, y;
public:
    point(int xx = 0, int yy = 0)
    {
        x = xx;
        y = yy;
        cout << "Constructor" << endl;
    }
    point(const point &p)
    {
        x = p.x;
        y = p.y;
        cout << "Copy Constructor" << endl;
    }
    ~point()
    {
        cout << "Destructor" << endl;
    }
    int get_x()
    {
        return x;
    }
    int get_y()
    {
        return y;
    }
};

void f(point p)
{
    // copy constructor
    cout << p.get_x() << "  " << p.get_y() << endl;
    // destructor
}

point g()
{
    point a(7, 33); //constructor
    return a; // copy constructor    temp object
}

void test()
{
    point a(15, 22); // constructor
    point b(a); //(1) copy constructor
    cout << b.get_x() << "  " << b.get_y() << endl; // 15 22
    f(b);//  (2) copy constructor
    b = g(); // (3) copy constructor
    cout << b.get_x() << "  " << b.get_y() << endl; // 7  33
}

int main()
{
    test();
    return 0;
}
/*
Constructor
Copy Constructor
15      22
Copy Constructor
15      22
Destructor
Constructor
Copy Constructor
Destructor
Destructor
7       33
Destructor
Destructor
*/

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

class OBJ1
{
public:
    OBJ1()
    {
        cout << "OBJ1\n";
    }
};

class OBJ2
{
public:
    OBJ2()
    {
        cout << "OBJ2\n";
    }
};

class Base1
{
public:
    Base1()
    {
        cout << "Base1\n";
    }
};

class Base2
{
public:
    Base2()
    {
        cout << "Base2\n";
    }
};

class Base3
{
public:
    Base3()
    {
        cout << "Base3\n";
    }
};

class Base4
{
public:
    Base4()
    {
        cout << "Base4\n";
    }
};

class Derived : public Base1, virtual public Base2,
    public Base3, virtual public Base4
{
public:
    Derived() : Base4(), Base3(), Base2(),
        Base1(), obj2(), obj1()
    {
        cout << "Derived.\n";
    }
protected:
    OBJ1 obj1;
    OBJ2 obj2;
};

void test()
{
    Derived aa;
    cout << "This is ok.\n";
}

int main()
{
    test();
    return 0;
}
/*
Base2
Base4
Base1
Base3
OBJ1
OBJ2
Derived.
This is ok.
*/

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

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

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

class Base3
{
public:
    Base3()
    {
        cout << "Base3 *" << endl;
    }
};

class Derived : public Base2,  public Base1, virtual public Base3
{
public:
    Derived(int a, int b, int c, int d, int e)
        : Base1(a), b2(d), b1(c), Base2(b)
    {
        m = e;
        cout << "Derived.\n";
    }
protected:
    Base1 b1;
    Base2 b2;
    Base3 b3;
    int m;
};

void test()
{
    Derived aa(1, 2, 3, 4, 5);
    cout << "This is ok.\n";
}

int main()
{
    test();
    return 0;
}
/*
Base3 *
Base2 2
Base1 1
Base1 3
Base2 4
Base3 *
Derived.
This is ok.
*/