Question

我正在创建一个异常类，只是在cout上报告问题并退出程序，如下所示：

class Exception {
protected:
    short code;
    string text;
public:
    friend ostream& operator <<(ostream& out, const Exception& p_exception) {
        return out << p_exception.text;
    }
    void execute() { cout << text; exit(code);
};

以及它的具体例子：

class IndexOutOfBoundsException : public Exception {
public:
    IndexOutOfBoundsException() {
        this->text = "\nERR:    An unsuccessful attempt was made to access the index outside the bounds of the array!";
        code = 1;
    }
};
class IndexOfEmptyFieldException : public Exception {
public:
    IndexOfEmptyFieldException() {
        this->text = "\nERR:    An unsuccessful attempt was made to access the index of an empty field!";
        code = 2;
    }
};
class AllocationFailureException : public Exception {
public:
    AllocationFailureException() {
        this->text = "\nERR:    An unsuccessful attempt was made to allocate dynamic memory!";
        code = 3;
    }
};

在我的脑海里，这一切看起来都非常整洁，但现在它似乎并不是一个好的OOP例子。当我思考它时，我发现我可以以某种方式使用静态成员，比如使int code;成为继承类特有的静态变量。或者，我可以使用void generate();使方法= 0成为纯虚函数，这是我的第一个想法。

我的问题是：是否有可能使此解决方案成为更好的OOP示例和/或我是否错过了OOD的一般要点？

Answer 1

这是一个示例，它减少了对象占用空间并使内存分配远离throw子句：

class Exception {
protected:
  short code;
  const string &text;
  Exception(short code, const string &text) :
    code(code), text(text)
  {}
...
}

class IndexOutOfBoundsException : public Exception {
private:
  static const string c_text = "\nERR:    An unsuccessful attempt was made to access the index outside the bounds of the array!";
public:
  IndexOutOfBoundsException() : Exception(1, c_text)
  { }
};

类继承：静态成员和虚方法

1 个答案: