如何从构造中寻址变量以便在同一类的方法中使用？

Question

我有这段代码：

class Passport
{
public:
    Passport()
    {
        std::vector<std::string> class_people(people,people+6); 
        std::vector<std::string> class_birth(birth,birth+6);
    }

    void show_data() {
        std::copy(class_people.begin(), class_birth.end());  
    }
};

当我尝试在class_people中使用show_data()时，编译器会抱怨该变量未被声明。

Answer 1

如果您希望所有成员函数都能访问变量，则需要将其作为类的成员变量：

html {
    font-size: 18px;
}

h1 {
    font-size: 1rem;
}

@media only screen and (min-device-width: 700px) {
    html {
        font-size: 19px;
    }
    h1 {
        font-size: 1.5rem;
    }
}

当然，您的构造函数需要进行一些调整（我假设class Passport { std::vector<std::string> class_people; std::vector<std::string> class_birth; public: Passport(): class_people(people,people+6), class_birth(birth,birth+6) {} }; 和people是全局的，就像在您的代码示例中一样）。

Answer 2

假设构造函数采用初始化参数

    class Passport {
      std::vector<std::string> class_people; 
      std::vector<std::string> class_birth;

    public:
      Passport(const char* people[], const char* birth[])
        : class_people(people,people+sizeof(people)/sizeof(people[0]))
        , class_birth(birth,birth+sizeof(birth)/sizeof(birth[0]))
      {}

};