第11周 程序阅读——继承和派生 自选阅读（2)

#include <iostream>
using namespace std;
class A
{
protected:
    int x;
public:
    A(int x)
    {
        A::x=x;
        cout<<"class A"<<endl;
    }
};
class B
{
private:
    A a1;
public:
    B(int x):a1(x)
    {
        cout<<"class B"<<endl;
    }
};
class C:public B
{
private:
    A a2;
public:
    C(int x):B(x),a2(x)
    {
        cout<<"class C"<<endl;
    }
};
class D:public C
{
public:
    D(int x):C(x)
    {
        cout<<"class D"<<endl;
    }
};
int main()
{
    D dobj(10);
    return 0;
}

实际运行结果：