c++ - C++重载运算符[]

我制作了一个应用程序，在其中输入要输入的书籍数量并使用重载运算符（[]），但是每次我提供存储数组的指针时，都会出现如下错误：


  2 IntelliSense：表达式必须具有整数或无作用域的枚举
  类型行：11列：24图书馆书籍


和


  错误1错误C2440：“正在初始化”：无法从
  'std :: string'到'unsigned int'Line：11 Column：1 Library Books


但是无论如何这是我的代码：

#include <iostream>
#include <string>
using namespace std;

class Books{
private:
    string* storage;
    string book;
public:
    Books(){
        storage = new string[book];
    }
    void savebooks(int iterate){
        for (int i = 0; i < iterate; ++i){
            cout << "Book: ";
            getline(cin, storage[i]);
        }
    }

    const string operator[](const int ref){
        return storage[ref];
    }
    ~Books(){
        delete storage;
    }
};

int main(){
    //local variables
    int quantity;
    //user display
    cout << "Welcome to Book Storage Viewer" << endl;
    cout << "How many books would you like to insert: ";
    cin >> quantity;
    //instantiante
    Books bk;
    //other handle
    bk.savebooks(quantity);
    //display books
    cout << "These are the books you've entered" << endl;
    for(int i = 0; i < quantity; ++i){
        cout << bk[i] << endl;
    }
    system("pause");
    return 0;
}

我也不是100％知道我是否正确编写了代码，如果还有错误，请告诉我，谢谢。

最佳答案

这个说法

    storage = new string[book];

是无效的。下标值应具有整数或未限定范围的枚举类型。

看来您的课程定义有错字，而不是

string book;

应该有例如

int book;

我认为你的意思是

private:
    string* storage;
    int quantity;
public:
    Books( int quantity) : quantity( quantity ) {
        storage = new string[this->quantity];
    }
    void savebooks(){
        for (int i = 0; i < quantity; ++i){
            cout << "Book: ";
            getline(cin, storage[i]);
        }
    }
//...

并且主要应该有

int quantity;
//user display
cout << "Welcome to Book Storage Viewer" << endl;
cout << "How many books would you like to insert: ";
cin >> quantity;
//instantiante
Books bk();
bk.savebooks();

关于c++ - C++重载运算符[]，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/22186907/