c++ - _BLOCK_TYPE_IS_VALID(pHead->nBlockUse) 在 "return 0"之后

Question

我正在编写一个程序，我必须在其中编写自己的字符串类和药水类。我知道这个运行时错误通常是在程序删除未分配的内容时引起的，但它发生在 main 中的“return 0”之后。我已经逐行调试它并尝试了一些方法来尝试消除运行时错误，但没有任何效果。有没有人可以帮我解决这个问题？

这是我的代码:

//Main
#include "Potion.h"
#include <iostream>
using std::cout;
using std::endl;

void TotalCost( Potion ArrayofPotions[5] )
{
    String Currency[4] = {"Platinum", "Gold", "Silver" ,"Copper"};
    int TotalCost[4] = {0, 0, 0, 0};
    int Cost[4] = {0, 0, 0, 0};

    for (short i = 0; i < 5; i++)
    {
        for (short k = 0; k < 4; k++)
        {
            Cost[k] = ArrayofPotions[i].ConvertCost(k);
            TotalCost[k] += Cost[k];

            if ( i != 0 )
                TotalCost[k] = ArrayofPotions[k].CalculateCost(TotalCost[k - 1], TotalCost[k]);
        }
    }
    cout << "\nTotal cost for all potions: ";

    for (short i = 0; i < 4; i++)
    {
        cout << TotalCost[i] << ' ';
        Currency[i].Display();
    }
}

int main()
{
    Potion Haggling("Potion of Haggling", "You haggle for 10% better prices for 30 seconds",
                "Weak", "0.80.0.4.");

    Potion Strength("Draught of Strength", "You can carry 20% more for 300 seconds", 
                "Low", "2.60.5.1.");

    Potion Health("Solution of Health", "You are 30% tougher for 60 seconds",
              "Mild", "2.20.5.1.");

    Potion Stealth("Philter of Stealth", "You are 40% harder to detect for 60 seconds",
               "Moderate", "0.90.5.1.");

    Potion Waterbreathing("Elixir of Waterbreathing", "You can breathe underwater for 60 seconds",
                      "Strong", "2.10.5.0.");

    Potion ArrayOfPotions[5] = {Haggling, Strength, Health, Stealth, Waterbreathing};

    for (short i = 0; i < 5; i++)
        ArrayOfPotions[i].DisplayPotions();

    TotalCost(ArrayOfPotions);

    system("pause");
    return 0;
}

//String class
class String
{
public:
    String() : m_str(nullptr)
    { }
    String(char chr) : m_str(nullptr)
    {
        m_str = new char;
        *m_str = ch;
    }
    String(char * str)
    {
        if (str != nullptr)
        {
            m_str = new char[strlen(str) + 1];
            strcpy(m_str, str);
        }
    }
    String(const String & copy) : m_str(copy.m_str)
    { }
    String& operator=(const String & rhs)
    {
        if ( this != &rhs )
        {
            delete [] m_str;
            m_str = new char[strlen(rhs.m_str) + 1];
            strcpy(m_str, rhs.m_str);
        }

        return *this;
    }
    ~String()
    {
        delete [] m_str;
    }
    void Display() const
    {
        cout << m_str;
    }
    char * GetStr() const
    {
        return m_str;
    }
    String Upper()
    {
        char * check = this->m_str;

        for (unsigned short i = 0; i < strlen( this->m_str ); i++, check++)
        {
            if ( *check > 96 && *check < 123 )
            {
                *check -= 32;
            }
            else
                m_str = this->m_str;
        }
        return m_str;
    }
private:
    char * m_str;
};

//Potion class

#include "String.h"

class Potion
{
public:    
    Potion() : m_name(nullptr), m_description(nullptr), m_potency(nullptr),
               m_cost(nullptr)
    { }
    Potion(String name, String description, String potency, String cost)
    {
        m_name = name;
        m_description = description;
        m_potency = potency.Upper();
        m_cost = cost;
    }
    Potion(const Potion & copy) : m_name(copy.m_name), m_description(copy.m_description),
                                  m_potency(copy.m_potency), m_cost(copy.m_cost)
    { }
    int ConvertCost(int index)
    {
        int cost = 0;
        char * new_cost = m_cost.GetStr();
        char * temp_string = new char[strlen( new_cost ) + 1];

        strcpy(temp_string, new_cost);

        char * temp = strtok( temp_string, "." );

        for (short k = 0; k != index; k++)
            temp = strtok( NULL, "." );

        cost = atoi( temp );

        delete [] temp_string;

        return cost;
    }
    int CalculateCost(int & cost1, int cost2)
    {
        if (cost > 99)
        {
            cost1++;
            cost2 -= 100;
        }
        return cost2;
    }
    void DisplayPotions()
    {
        String Currency[4] = {"Platinum", "Gold", "Silver" ,"Copper"};
        int cost = 0;

        m_name.Display();
        m_description.Display();
        m_potency.Display();

        for (short i = 0; i < 4; i++)
        {
            cost = ConvertCost(i);

            if (cost != 0)
            {
                cout << ConvertCost(i) << ' ';
                Currency[i].Display();
            }
        }
    }
private:
    String m_name;
    String m_description;
    String m_potency;
    String m_cost;
};

很抱歉，它真的很长，我遗漏了一些输出格式，但我真的需要一些帮助。

附言我的教授希望我们将成本从字符串转换为 int，并且必须将其放入“0.0.0.0”格式。这就是为什么它是这样写的。

Answer 1

您的赋值运算符已损坏，因为它从右侧复制了指针。
您需要遵循与复制构造函数中相同的过程。

顺便说一句，复制构造函数也被破坏了，因为如果 rhs 为空，它将失败。

(在空字符串的表示中使用空字符串是一个更安全的想法(即使用 "" 而不是 nullptr)。
它使您免于进行大量空检查。)

这个构造函数也坏了:

String(char * str)
{
    if (str != nullptr)
    {
        m_str = new char[strlen(str) + 1];
        strcpy(m_str, str);
    }
}

因为如果您将 m_str 传递给 nullptr ，它会保留未初始化的状态 - 您会经常这样做。

这个构造函数也坏了:

String(char chr) : m_str(nullptr)
{
    m_str = new char;
    *m_str = ch;
}

因为它不构造以零结尾的字符串。

你需要

m_str = new char[2];
m_str[0] = ch;
m_str[1] = 0;