将构造函数值从子类传递到超类c++ [重复]

Posted 2023-02-23

【中文标题】将构造函数值从子类传递到超类c++ [重复]

【英文标题】：Pass constructor values from subclass to superclass c++ [duplicate]

【发布时间】：2018-05-08 15:11:40

【问题描述】：

我正在编写一个程序，其中超类“Entry”模拟一个库输入，其中有几个子类。其中之一是musicAlbum。

entry 有一个带有两个字符串参数的构造函数，用于获取借用项目的名称和年份。然后子类 musicAlbum 有一个构造函数来设置几个字符串参数（艺术家和唱片标签）以及在超类中检索的参数。但是我收到一条错误消息，指出超类中没有默认构造函数，所以我相信我做错了一些非常明显但我看不到的错误。

有什么帮助吗？

这是超类：

Class entry 

protected:
    int borrowed;
    string name, borrowedBy, year;

public:

entry(string cborrowedBy, string cyear) 
    borrowed = 1; //Borrowed changes to 1 to indicate that is currenty borrowed
    year = cyear;
    borrowedBy = cborrowedBy;
;    

virtual void entryBorrowed(string fname) 
    name = fname;
;
void entryReturned() 
    borrowed = 0;
; // Calling this functions changes int borrowed into 0 to indicate that has been returned
virtual void printDetails() ;

;

这是子类：

    class musicAlbum : public entry 

protected: 

    string artist, recordLabel;

public:
    musicAlbum(string cmborrowedBy, string cmyear, string cartist, string crecordLabel)
         entry(cmborrowedBy, cmyear);
         artist = cartist;
         recordLabel = crecordLabel;

    
    void entryBorrowed(string fname) 

        name = fname;



    
    void printDetails() 

        cout << "This entry borrowed by: " << borrowedBy << " in " << year
            << endl << endl << "Name: " << name << endl << "Artist: " << artist << endl << "Record Label: " << recordLabel << endl;


    ;


;

【参考方案1】：

你可以这样做：

musicAlbum(string cmborrowedBy, string cmyear, string cartist, string crecordLabel):entry(cmborrowedBy, cmyear)

   //...