我可以调用从 main() 覆盖的虚函数吗？

Question

我知道这个


// C++ program for function overriding 

#include <bits/stdc++.h> 
using namespace std; 

class base 
{ 
public: 
    virtual void print () 
    { cout<< "print base class" <<endl; } 

    void show () 
    { cout<< "show base class" <<endl; } 
}; 

class derived:public base 
{ 
public: 
    void print () //print () is already virtual function in derived class, we could also declared as virtual void print () explicitly 
    { cout<< "print derived class" <<endl; } 

    void show () 
    { cout<< "show derived class" <<endl; } 
}; 

//main function 
int main()  
{ 
    base *bptr; 
    derived d; 
    bptr = &d; 

    //virtual function, binded at runtime (Runtime polymorphism) 
    bptr->print();  

    // Non-virtual function, binded at compile time 
    bptr->show();  

    return 0; 
}

我可以打印

print derived class
show base class
show derived class

我可以打印吗

print base class

使用派生 class 的对象 d 仅更改 main() 而无需创建另一个对象？如果是怎么办？

Answer 1

can I print print base class with the object d of the derived class with just changing main()

是的，你可以。您必须在调用中明确使用基数 class。

bptr->base::print();

也可以直接使用d。

d.base::print();

我可以调用从 main() 覆盖的虚函数吗？

Can I call a virtual function that is overridden from main()?

c++

polymorphism

virtual-functions