Question

我已尝试过所有内容，但代码无效，我无法理解原因。

我有两节课。这是基类：

class Vegetables
{
    private:
        char *nameStr;
        char *countrySrc;
        int seasonRd;
    public:
        Vegetables()
        {
            cout << "Default constructor for Vegetables" << endl;
            nameStr = new char[20];
            nameStr = "Unknown";
            countrySrc = new char[20];
            countrySrc = "Unknown";
            seasonRd = -1;
        }

        virtual ~Vegetables()
        {
            delete[]nameStr; //Here happens the error (_crtisvalidheappointer(block))
            delete[]countrySrc;
            cout << "Destructor for Vegetables" << endl;
        }
};

它继承了类'Inherited Unit'：

class InhUnit : public Vegetables
{
    private:
        Delivery delivery_;
        Vegetables vegetables;
        int quantity;
        int price;
        int delivPrice;

    public:
        InhUnit() :Vegetables(),delivery_(OwnCosts), vegetables(), quantity(-1), price(-1), delivPrice(-1)
        {
            cout << "Default constructor for Inherited Unit" << endl;
        }

        ~InhUnit()
        {
            cout << "Destructor for Inherited Unit" << endl;
        }
};

弹出此错误的原因可能是什么？

Answer 1

这不是你复制字符串的方式，而是使用strcpy

    Vegetables()
    {
        cout << "Default constructor for Vegetables" << endl;
        nameStr = new char[20];
        strcpy(nameStr, "Unknown");
        countrySrc = new char[20];
        strcpy(countrySrc, "Unknown");
        seasonRd = -1;
    }

您正在做的是分配一些内存并将其分配给指针。然后在下一行中，您指定指向字符串的指针，而不是将字符串复制到您已分配的内存中。

当你调用delete[]因为指针没有指向你分配的内存时，你得到了一个错误。

Answer 2

你应该使用像std :: string这样的字符串类来避免这种指针问题。

Answer 3

更正代码

class Vegetables {
private:
    std::string nameStr;    // Use std::string instead of C-style string
    std::string countrySrc;
    int         seasonRd;

public:
    // Use constructor initialization list
    Vegetables() : nameStr("Unknown"), countrySrc("Unknown"), seasonRd(-1) {
        cout << "Default constructor for Vegetables" << endl;
    }

    virtual ~Vegetables() {
        cout << "Destructor for Vegetables" << endl;
    }
};

使用'delete'运算符清除内存时出现'Debug Assertion Failed'错误

3 个答案: