How to delete specific vector from given class in C++

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vector

C++14

Hello, I am writing a program that allows users to input a music album and store them into vectors. Then the program asks the user whether to borrow it. To do that I tried using .erase of the given vector. However the vector function is defined in a constructor of a class and the modification is done later with a different function but within the same class. Any help would be much appreciated, thank you.

What I have tried:

class Album :public Entry {
private:
        vector <string> vec;
	string singer, label;
	string combine; //to combine artist and record label
	int choice;
public:
	Album();
	void Borrow1() {};
};

Album::Album() {
	do
	{
		cout << "Enter the singer(type end to finish)" << endl;
		getline(cin, singer);
		if (singer == "end")
			break;
		cout << "Enter the label: " << endl;
		getline(cin, label);
		combine = singer + " ,by, " + label;
		cout << "The singer and label is: " << combine << endl;
		vec.push_back(combine);
	} while (true);

	cout << "you entered:  " << endl;
	for (int i = 0; i < vec.size(); i++) {
		cout << "Number " << i << ". Item is: " << vec[i] << endl;
	}
}

void Album::Borrow1() { 
	cout << "Which item is borrowed? Enter the number." << endl;
	cin >> choice;
	vec.erase(vec.begin() + choice);
	cout << "Done" << endl;
	cout << "The followings still remain:  " << endl;
	for (int i = 0; i < vec.size(); i++) {
		cout << "# : " << i << ". Album is: " << vec[i] << endl;
	}
}