C++构造函数按下列顺序被调用：
　　(1)任何虚拟基类的构造函数按照它们被继承的顺序构造；
　　(2)任何非虚拟基类的构造函数按照它们被继承的顺序构造；
　　(3)任何成员对象的构造函数按照它们声明的顺序调用；
　　(4)类自己的构造函数。
#include <iostream>
using namespace std;
class OBJ1
{
public:
OBJ1(){ cout <<"OBJ1 "; }
};
class OBJ2
{
public:
OBJ2(){ cout <<"OBJ2 "; }
};
class Base1
{
public:
Base1(){ cout <<"Base1 "; }
};
class Base2
{
public:
Base2(){ cout <<"Base2 "; }
};
class Base3
{
public:
Base3(){ cout <<"Base3 "; }
};
class Base4
{
public:
Base4(){ cout <<"Base4 "; }
};
class Derived :public Base1， virtual public Base2，
public Base3， virtual public Base4
{
public:
Derived() :Base4()， Base3()， Base2()，
Base1()， obj2()， obj1()
{
cout <<"Derived ok. ";
}
protected:
OBJ1 obj1;
OBJ2 obj2;
};
int main()
{
Derived aa;
cout <<"This is ok. ";
int i;
cin >> i;
return 0;
}
　　结果：
　　Base2
　　Base4
　　Base1
　　Base3
　　OBJ1
　　OBJ2
　　Derived ok.
　　This is ok.