C++衍生類別–基類建構函式,內嵌對象(子物件)的執行順序

來源:互聯網
上載者:User

與衍生類別建構函式的初始化列表順序無關,是按如下順序:

1.基類建構函式(按繼承時的順序)

2.子物件建構函式(按類中聲明的順序)

3.衍生類別自己的建構函式 

析構時:

與構造時相反

 

 

測試程式如下:

#include <iostream>
using namespace std;

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

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

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

class D
{
public:
 int d;
 D(){ cout << "D1" << endl; }
 D(int a):d(a){ cout << "D2" << endl; }
 ~D(){ cout << "~D" << endl; }
};

class E:public B, public A
{
public:
 D d;
 C c;
 E():A(),c(),B(),d(){ cout << "E" << endl; }
 ~E(){ cout << "~E" << endl; }
};

class F:public E,public A
{
public:
 C cf;
 D df;
 F():A(),cf(),df(5){  cout << "F" << endl; }
 ~F(){ cout << "~F" << endl; }
};

int main(int argc, _TCHAR* argv[])
{
 F f;
 return 0;
}

**************************************************************

輸出如下:

B
A
D1
C
E
A
C
D2
F
~F
~D
~C
~A
~E
~C
~D
~A
~B

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