cpp——类——成员访问权限

来源：互联网发布：杜蕾斯震动棒知乎编辑：程序博客网时间：2024/05/25 12:22

成员访问权限

class CAnimal{    int food1;    private:    int food2;    protected:    int food3;    public:    int food4;};class CDog : public CAnimal{public:    void feed()    {        //food1 = 1;  //CAnimal private        //food2 = 2;  //CAnimal private        food3 = 3;        food4 = 4;    }};class CHusky : public CDog{public:    void feed()    {        //food1 = 1;  //CAnimal private        //food2 = 2;  //CAnimal private        food3 = 3;        food4 = 4;    }};void member_access_privilege(){    CAnimal animal;    //animal.food1 = 1;  //CAnimal private    //animal.food2 = 2;  //CAnimal private    //animal.food3 = 3;  //CAnimal protected    animal.food4 = 4;        CDog dog;    //dog.food1 = 1;  //CAnimal private    //dog.food2 = 2;  //CAnimal private    //dog.food3 = 3;  //CAnimal protected    dog.food4 = 4;        CHusky husky;    //husky.food1 = 1;  //CAnimal private    //husky.food2 = 2;  //CAnimal private    //husky.food3 = 3;  //CAnimal protected    husky.food4 = 4;}

总结

成员访问权限大小：public > protected > private
成员默认访问权限为private
类外部只能访问public成员，不能访问protected和private成员
子类不能访问(继承)父类private成员，只能访问(继承)父类public和protected成员
所有成员(non-static数据成员，non-static函数成员，static数据成员，static函数成员)访问权限规则一致
成员访问权限只是c++源代码层控制机制(从业务逻辑层考虑)，因此编译阶段有区别，但在目标代码层无区别，因此链接阶段无区别

0 0