C++ 错误：不允许抽象类类型的对象

Question

Having trouble with inheritance. I do not know what is wrong with the script..

in main

int main(){
    Repository repo("dogs.txt");
    FileAdoptionList* a = new CSVDoglist{}; / here is the error
    Controller ctrl(repo, dogValidator{}, a);
    UI ui(ctrl);

    ui.startUI();

    delete a;
}

CSVDoglist.h

class CSVDoglist : public FileAdoptionList
{
public:

    void writeToFile();
    void displayAdoptionlist() const;
};

FileAdoptionList.h

class FileAdoptionList : public AdoptionList
{
protected:
    std::string filename;

public:
    FileAdoptionList();
    virtual ~FileAdoptionList() {}

    void setFilename(const std::string& filename);
    virtual void writeToFile() = 0;
    virtual void displayAdoptionList() const = 0;
};

AdoptionList.h

class AdoptionList
{
protected:
    std::vector<Dog> storage;

public:
    AdoptionList();

    // Adds a dog to the playlist.
    void add(const Dog& dog);
    // Checks if the adoptionlist is empty.
    bool isEmpty();

    virtual ~AdoptionList() {}
};

ERRORS:

object of abstract class type "CSVDoglist" is not allowed:  

'CSVDoglist': cannot instantiate abstract class Adoptig Dogs    

I have read more topics about this problem but I didn't found the solution.

Can someone help me? Thanks

Answer 1

It seems you have a typo.

A function named displayAdoptionlist (contains small l ) is declared in CSVDoglist , but the pure virtual function displayAdoptionList (contains large L ) isn't overrided in CSVDoglist .