c++结构体

#include<iostream> 
#include<cstdio>
using namespace std;

struct Biological{
public:
    string property;
    virtual void prop(){
        cin>>property;
        cout<<"property:"<<property<<endl;
    }    

private:  // c++默认权限为private
    string name;
    void species(){
        cin>>name;
        cout<<"name:"<<name<<endl;
    }

protected:
    string belong;
    void bel(){
        cin>>belong;
        cout<<"belong:"<<belong<<endl;
    }
};

struct Animal:public Biological{// 公有继承为默认可以省略
public:
    void display(){
        prop();
        bel();
        // species();  // error: ‘void Biological::species()’ is private 
    }
};

struct Plant:private Biological{  
public:
    void display(){
        prop();
        bel();
        //species();  // error: ‘void Biological::species()’ is private
    }
};

struct Both:protected Biological{  // 私有继承
public:
    void display(){
        prop();
        bel();
        //species();  // error: ‘void Biological::species()’ is private
    }
};

void animalDis(){
    Animal animal;
    animal.display();
    animal.property="cat";
    cout<<"修改animal.property为:"<<animal.property<<endl;
    // animal.name="xiaohei";  // error: ‘std::__cxx11::string Biological::name’ is private
    // cout<<"animal.name"<<animal.name<<endl;
    // animal.belong="animal";  // error: ‘std::__cxx11::string Biological::belong’ is protected
    // cout<<"animal.belong"<<animal.belong<<endl;
}

void plantDis(){
    Plant plant;
    plant.display();
    // plant.property="tree";  // error: ‘std::__cxx11::string Biological::property’ is inaccessible
    // cout<<"修改plant.property为:"<<plant.property<<endl;
    // plant.name="poplar";  //error: ‘std::__cxx11::string Biological::name’ is private
    // cout<<"修改plant.name为:"<<plant.name<<endl;
    // plant.belong="plant";  //error: ‘std::__cxx11::string Biological::belong’ is protected
    // cout<<"修改plant.belong为:"<<plant.belong<<endl;
}

void bothDis(){
    Both both;
    both.display();
    // both.property="tree";  // error: ‘std::__cxx11::string Biological::property’ is inaccessible
    // cout<<"修改both.property为:"<<both.property<<endl;
    // both.name="poplar";  // error: ‘std::__cxx11::string Biological::name’ is private
    // cout<<"修改both.name为:"<<both.name<<endl;
    // both.belong="plant";  // error: ‘std::__cxx11::string Biological::belong’ is protected
    // cout<<"修改both.belong为:"<<both.belong<<endl;
}

int main(){
    animalDis();
    plantDis();
    bothDis();
    return 0;
}