Question

我是C ++的初学者，我在过去的4个月里一直在学习。我们有一个为学校做的任务;使用我们迄今为止从C ++学到的知识创建基于文本的冒险游戏。今天我们去了课程，继承和指针，所以我认为我可以使用类/继承进行一些练习。

到目前为止我的代码是：

Character.h （标题文件）

#ifndef CHARACTER_H
#define CHARACTER_H
#include <cstdlib>

class Character
{
private:
    int Health;

public:
    Character();
    ~Character();

    int  GetHealth()                        {return Health;}
    void SetHealth(int newHealth)           {Health = newHealth;}       


};

class Monster:public Character
{
    int  GetHealth()                        {return Health;} 
    void SetHealth(int newHealth)           {Health = rand()% 50+100;}
}

#endif

Character.cpp

#include "Character.h"

Character::Character()
{
    Health = 100;
}

Character::~Character()
{
}

Battle.cpp （一切都在哪里发生）

#include <iostream>
#include <cstdlib>
#include "Character.h"
using namespace std;

int main()
{
    Character* Player = new Character();
    Monster* Monster1 = new Monster();

    cout << "Player's Health is: " << Player->SetHealth << endl << endl;
    cout << "Monster's Health is: " << Monster1->SetHealth << endl << endl;
}

让我解释一下我要做的事情......

我只是想让程序显示玩家和怪物的健康状况。

在字符头文件中，类＆＃39;字符＆＃39;是游戏中每个角色的基础。然后我获取并设置课程的健康状况。然后，我试图创建一个名为“怪物”的儿童课程。来源于“角色”＃39;类。与标准角色类相比，这将具有不同的健康状况，但我不确定如何做到这一点。我想让健康随机生成50到100之间。然后在＆＃39; Battle.cpp＆＃39;文件我正在尝试创建一个名为＆＃39; Player＆＃39;其中包括默认的生命值（100）和一个叫做怪物1的新怪物。然后我想显示两个角色的健康状况。我还打算创造出具有不同健康状况的多个怪物。

当我尝试运行该程序时，我似乎得到了大量的错误，并且说出了#City of Character :: Health＆＃39;。

我不太确定我做错了什么，因为我还是比较新的C ++并且仍然试图了解指针和继承的概念。

Answer 1

让我回答一下代码：

#ifndef CHARACTER_H
#define CHARACTER_H
#include <cstdlib>

class Character
{
    // this property will be used in the derived classes, we need protected instead of private
protected:
    int Health;

public:
    Character();
    ~Character();

    // This method is to be repeated in the derived class, and publicly accessible
    // (not only inside the class, but also outside (like you do in main())
public:
    int  GetHealth()                        {return Health;}
    // This method needs to be redefined in Monster, that's a candidate for a virtual method
    virtual void SetHealth(int newHealth)           {Health = newHealth;}       


};

class Monster:public Character
{
    // You don't need this anymore - the GetHealth from class Character is accessible
    // int  GetHealth()                        {return Health;} 

    // you override a method - write a different version. Use virtual to note that
    virtual void SetHealth(int newHealth)           {Health = rand()% 50+100;}
}; // lacked a semi-colon here :)

#endif

Battle.cpp的代码

#include <iostream>
#include <cstdlib>
#include "Character.h"

using namespace std;

int main()
{
    Character* Player = new Character();
    Monster* Monster1 = new Monster();

    // The moment you cout, you need to provide a value (a method that returns something).
    // You want to "GetHealth()" in order to show it :)
    cout << "Player's Health is: " << Player->GetHealth() << endl << endl;
    cout << "Monster's Health is: " << Monster1->GetHealth() << endl << endl;
}

我也不喜欢你在课堂上对Health所做的事情。首先你声明它private - 所以没有人可以以未经授权的方式改变它。然后你声明一个普通的SetHelth()，它允许你对值做任何事情。

相反，您可以在构造函数中创建初始值：

#ifndef CHARACTER_H
#define CHARACTER_H
#include <cstdlib>

class Character
{
    // this property will be used in the derived classes, we need protected instead of private
protected:
    int Health;

public:
    Character();
    ~Character();

    // This method is to be repeated in the derived class, and publicly accessible
    // (not only inside the class, but also outside (like you do in main())
public:
    int  GetHealth()                        {return Health;}
};

class Monster:public Character
{
    // You don't need this anymore - the GetHealth from class Character is accessible
    // int  GetHealth()                        {return Health;} 

public:
    Monster();
}; // lacked a semi-colon here :)

#endif

和Character.cpp

#include "Character.h"

Character::Character()
{
    Health = 100;
}

Character::~Character()
{
}

Monster::Monster()
{
    Health = rand()% 50+100;
}

然后您可以使用DrinkHealthPotion();或GetDamage();

等方法进行更改

Answer 2

我认为你的问题可能是一个错字，你写的是：

cout << "Player's Health is: " << Player->SetHealth << endl << endl;
cout << "Monster's Health is: " << Monster1->SetHealth << endl << endl;

我认为您的意思是GetHealth而不是SetHealth，GetHealth也是一个函数，因此您必须使用括号GetHealth()来调用它。

所以我相信你想要它说：

cout << "Player's Health is: " << Player->GetHealth() << endl << endl;
cout << "Monster's Health is: " << Monster1->GetHealth() << endl << endl;

希望能帮助您，并祝您在未来使用C ++付出更多努力

C ++继承和指针错误（初学者）

2 个答案: