访问 Class 对象以与全局变量进行比较
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【中文标题】访问 Class 对象以与全局变量进行比较【英文标题】：Accessing Class objects to compare with global variables 【发布时间】：2019-12-04 05:13:04 【问题描述】：我正在制作一个文本存储菜单。我有一个基本的武器类，其中包含一个用于名称和武器声音的字符串，一个 bool 表示您是否已经拥有该物品，一个 double 表示价格。
我正在尝试将类中的双倍价格与全局变量 p_balance（玩家余额）进行比较 检查玩家是否买得起该物品
这是课程
class Weapon
public:
string name, sound;
bool owned = false;
double price;
public:
Weapon() //Default Constructor
name = "name";
sound = "sound";
owned = owned;
price = 0;
Weapon(string i_name, string i_sound, bool i_owned, double i_price)//Constructor
name = i_name;
sound = i_sound;
owned = i_owned;
price = i_price;
void displayItems();
cout << name << " - " << price << "g." << endl;
;
（我知道我知道我应该将 Weapons[i] 切换到 Weapons[i] 以使我的生活更轻松）
这是我最近一次访问它的尝试
while (p_balance < Weapons[0].getPrice()) // Not enough gold
cout << "Sorry, it seems you don't have enough gold." << endl;
goto MainMenu;
我曾尝试在类中创建一个方法来获取价格，但没有成功，但这就是为什么它调用了一个不存在的方法
我也玩过 if 循环，但它变得凌乱并且显示的信息比我喜欢的要多 在所有者资金检查之后，我让它执行所有权检查并检查该项目插槽是否配备了某些东西，但是当我使用嵌套的 if 语句时，即使第一个 if (price) 失败，它也会显示所有这些语句的结果，所以我想出一个 while 语句？
我不是在寻找答案，因为我想学习，但上次我在这里发帖时，我得到了一些真正帮助我的很好的提示，我对此感到沮丧，所以我想我会问求助！
编辑：
我考虑了你们所说的，然后又回到了伪。 我对现在的情况很满意：
#include <iostream>
#include <string>
using namespace std;
int p_choice;
double p_balance = 125;
//Simple Weapon Class
class Weapon
public:
int slot;
string name, sound;
bool owned = false;
double price;
public:
Weapon() //Default Constructor
slot = 0;
name = "name";
sound = "sound";
owned = owned;
price = 0;
Weapon(int i_slot, string i_name, string i_sound, bool i_owned, double i_price)//Constructor
slot = i_slot;
name = i_name;
sound = i_sound;
owned = i_owned;
price = i_price;
double* p_ptr;
p_ptr = &price;
void displayItems();
int x = 0;
cout << slot << " - " << name << " - " << price << "g." << endl;
;
int main()
int p_selection;
bool hasWeapon, offHand, inStore;
hasWeapon = false;
offHand = false;
inStore = true;
//Weapon Array
cout << "---------------------------------------------" << endl;
Weapon Weapons[6];
Weapons[0] = Weapon(1, "Great Sword of Greatening", "Tssng", false, 50);
Weapons[1] = Weapon(2, "Claw", "Thwack", false, 10);
Weapons[2] = Weapon(3, "Silent Pea-shooter", "Pew Pew", false, 15);
Weapons[3] = Weapon(4, "Loudening Silencer Attachment", "...", false, 5);
Weapons[4] = Weapon(5, "Tiger-Repelling Rock ", "Meooowraaarah", false, 25);
Weapons[5] = Weapon(6, "The Stick of Truth", "How do you kill that which has no life", false, 100);
cout << "---------------------------------------------" << endl;
cout << "Welcome to my store, traveller!" << endl;
cout << "How can I help you?" << endl;
//Menu
do
cout << "1. Buy" << endl;
cout << "2. Check Balance" << endl;
cout << "3. Exit" << endl;
cin >> p_choice;
if (p_choice == 1)
//Ask player which weapon the want to buy
cout << "Which item are you interested in?" << endl;
cout << "(Choose using 1-6)" << endl;
cin >> p_selection;
if (p_selection >= 1 && p_selection <= 6)
int i_choice = p_selection - 1;// Take one off the choice so it corresponds correctly to the object in the array
if (Weapons[i_choice].owned == false && p_balance >= Weapons[p_selection].price)// check if item is owned/can be bought
if (hasWeapon == false)// flip "Slot" flag
hasWeapon = true;
Weapons[i_choice].owned = true;// flip ownership flag
p_balance = p_balance - Weapons[i_choice].price; // update balance
cout << "Good eye, that's a fine item! Enjoy your " << Weapons[i_choice].name << endl;
else if (Weapons[i_choice].price > p_balance)
cout << "Seems you're a little short on gold..." << endl;
else if (Weapons[i_choice].owned == true)
cout << "Seems you don't know how to dual wield, why don't you pick something else." << endl;
// Check Balance
if (p_choice == 2)
cout << "Your balance is: " << p_balance << "g." << endl;
// Leave
if (p_choice == 3 && inStore == true)
cout << "Thanks for stopping by! Good luck out there!" << endl;
inStore = false;
else if (p_choice == 3 && hasWeapon == false)
cout << "You're gonna want a weapon out there, traveller" << endl;
while (inStore == true);
//Scenario
bool scenario = true;
cout << "Inventory" << endl;
for (int x = 0; x < 6; x++)
if (Weapons[x].owned == true)
//convey slot
cout << "Press " << Weapons[x].slot << " to use your " << Weapons[x].name << endl;
cin >> p_choice;
do
for (int y = 0; y < 1; y++)
int use = p_choice - 1;
if (Weapons[use].owned == true)
cout << Weapons[use].sound << endl;
while (scenario == true);
system("pause");
return 0;
唯一的问题是它不停地播放“声音”，for循环试图让它运行1次哈哈
【问题讨论】：
在您最喜欢的 C++ 参考中搜索“初始化列表”。 我建议您更改设计以避免goto。没有适当纪律的 goto 语句可能会调用意大利面条式代码和不需要的行为。
看起来你需要花更多的时间设计你的程序而不是编码。例如，您需要确定在哪里需要循环而不是使用条件语句。
1.您在构造函数的定义中声明/定义一个函数。 2. 你在“displayItems()”的声明和定义之间多加了一个分号。
全局变量“p_balance”在哪里声明？如果在其他文件中声明，则需要搜索“extern”的用法。
【参考方案1】：
这是最终产品
#include <iostream>
#include <string>
using namespace std;
int p_choice;
double p_balance = 125;
//Simple Weapon Class
class Weapon
public:
int slot, durability;
string name, sound;
bool owned = false;
double price;
public:
Weapon() //Default Constructor
slot = 0;
name = "name";
sound = "sound";
owned = owned;
price = 0;
durability = 0;
Weapon(int i_slot, string i_name, string i_sound, bool i_owned, double i_price, int i_durability)//Constructor
slot = i_slot;
name = i_name;
sound = i_sound;
owned = i_owned;
price = i_price;
durability = i_durability;
void displayItems();
int x = 0;
cout << slot << " - " << name << " - " << price << "g." << endl;
;
int main()
int p_selection;
bool hasWeapon, offHand, inStore;
hasWeapon = false;
offHand = false;
inStore = true;
//Weapon Array
cout << "---------------------------------------------" << endl;
cout << "For Sale:" << endl;
Weapon Weapons[6];
Weapons[0] = Weapon(1, "Great Sword of Greatening", "Tssng", false, 50, 25);
Weapons[1] = Weapon(2, "Claw", "Thwack", false, 10, 15);
Weapons[2] = Weapon(3, "Silent Pea-shooter", "Pew Pew", false, 15, 20);
Weapons[3] = Weapon(4, "Loudening Silencer Attachment", "...", false, 5, 5);
Weapons[4] = Weapon(5, "Tiger-Repelling Rock ", "Meooowraaarah", false, 25, 30);
Weapons[5] = Weapon(6, "The Stick of Truth", "How do you kill that which has no life", false, 100, 50);
cout << "---------------------------------------------" << endl;
cout << "Welcome to my store, traveller!" << endl;
cout << "How can I help you?" << endl;
//Menu
do
cout << "1. Buy" << endl;
cout << "2. Check Balance" << endl;
cout << "3. Exit" << endl;
cin >> p_choice;
if (p_choice == 1)
//Ask player which weapon the want to buy
cout << "Which item are you interested in?" << endl;
cout << "(Choose using 1-6)" << endl;
cin >> p_selection;
if (p_selection >= 1 && p_selection <= 6)
int i_choice = p_selection - 1;// Take one off the choice so it corresponds correctly to the object in the array
if (Weapons[i_choice].owned == false && p_balance >= Weapons[p_selection].price)// check if item is owned/can be bought
if (hasWeapon == false)// flip weapon flag
hasWeapon = true;
Weapons[i_choice].owned = true;// flip ownership flag
p_balance = p_balance - Weapons[i_choice].price; // update balance
cout << "Good eye, that's a fine item! Enjoy your " << Weapons[i_choice].name << endl;
else if (Weapons[i_choice].price > p_balance)
cout << "Seems you're a little short on gold..." << endl;
else if (Weapons[i_choice].owned == true)
cout << "Seems you don't know how to dual wield, why don't you pick something else." << endl;
cout << "(You already own this item)" << endl;
// Check Balance
if (p_choice == 2)
cout << "Your balance is: " << p_balance << "g." << endl;
// Leave
if (p_choice == 3 && inStore == true)
cout << "Thanks for stopping by! Good luck out there!" << endl;
inStore = false;
else if (p_choice == 3 && hasWeapon == false)
cout << "You're gonna want a weapon out there, traveller" << endl;
while (inStore == true);
//Scenario
bool scenario, equipped;
int attack, equip, choose;
equipped = false;
scenario = true;
do
Equip:
cout << "----------------------------------------------------" << endl;
cout << " Inventory" << endl;
for (int x = 0; x < 6; x++)
if (Weapons[x].owned == true)
//convey slot and display equippable items
cout << Weapons[x].slot << " - " << Weapons[x].name << " - Uses Left: " << Weapons[x].durability << endl;
cout << "----------------------------------------------------" << endl;
cout << endl;
cout << "What would you like to equip? (Select using the given number + Enter)" << endl;
cout << "(Press 9 to quit)" << endl;
cin >> choose;
equip = choose - 1;
if (choose == 9)
scenario = false;
else if (Weapons[equip].owned == true)
int action;
cout << "You have equipped " << Weapons[equip].name << endl;
Action:
cout << "Press 1 and Enter to use." << endl;
cout << "Press 2 and Enter to equip a new item" << endl;
cout << "Press 3 and Enter to go home" << endl;
cin >> action;
if (Weapons[equip].durability <= 0)// cant use broken items
cout << "That item appears to have broken!" << endl;
else if (action == 1 && Weapons[equip].durability >= 0)// attack and durability check
cout << Weapons[equip].sound << endl;
cout << endl;
Weapons[equip].durability--;// durability decrement
goto Action;
else if (action == 2)// change equip
goto Equip;
else if (action == 3)// exit
scenario = false;
while (scenario == true);
cout << endl;
cout << "I wish you a safe journey home, traveller." << endl;
system("pause");
return 0;
再次感谢您的指导。
【讨论】：
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