c++ - 只定义在一个类中

Question

#include <iostream>
#include <cstdlib>
#include <iomanip>
#include <string>
using namespace std;
class Meny
{
public:
    void Meny2()
    {
        cout << "Welcome " << Name << LastName;
    }
};

class Kund
{
public:
    string  Name, LastName, personnummer;

    void LoggaIn()
    {
        cout << "Please enter your full name: " << endl;
        cin >> Name >> LastName;
        cout << "Please enter your social security number: " << endl;
        cin >> personnummer;
    }
};

所以目前cout << "Welcome " << Name << LastName;不会工作因为Name和 LastName在 Meny 中未定义类，有没有办法让它们被定义，即使它们是在另一个类中定义的？

Answer 1

Name 和 LastName 不是 Meny 的属性。它们是 Kund 的属性。所以这些属性是不可访问的。您必须以某种方式使其易于访问。

#include <iostream>
#include <cstdlib>
#include <iomanip>
#include <string>
using namespace std;

class Kund
{
public:
    string  Name, LastName, personnummer;

    void LoggaIn()
    {
        cout << "Please enter your full name: " << endl;
        cin >> Name >> LastName;
        cout << "Please enter your social security number: " << endl;
        cin >> personnummer;
    }
};

class Meny
{
public:
    void Meny2(const Kund& k) const
    {
        cout << "Welcome " << k.Name << k.LastName;
    }
};

或子类

class Meny: public Kund
{
public:
    void Meny2() const
    {
        cout << "Welcome " << Name << LastName;
    }
};

或模板

template <typename T>
class Meny: public T
{
public:
    void Meny2() const
    {
        cout << "Welcome " << Name << LastName;
    }
};

或者在函数中使用模板

class Meny
{
public:
    template <typename T>
    void Meny2(const T& k) const
    {
        cout << "Welcome " << k.Name << k.LastName;
    }
};