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Why does my SaveToFile function not work?

PoorBoiz (38)
I try to save my input to a text file in a format which each information is divided by a comma. But it doesn't work. What mistake did I make here? What should I do?

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void SaveToFile(string filename) {
	ofstream f("employee.txt");
	Employee *emp;
	Manager* man;
	f.open("employee.txt", std::ios_base::binary | std::ios_base::app);
	for (int i = 0; i < list.size(); i++) {
		emp = list.get(i);
		man = dynamic_cast<Manager*>(emp);
		if (f.is_open())
		{
			f.write(reinterpret_cast<char*>(&list), sizeof(list));
			f << emp->getMaSo() << "," << emp->getTen() << "," <<
				emp->getNgaySinh() << "," << emp->getEmail() << "," <<
				emp->getDienThoai() << "," << emp->getDiaChi() << "," <<
				emp->getLuongCoBan() << "," << man->getChucVu() << ","
				<< man->getHeSoChucVu() << "," << man->getThuong() << endl;
		}
	}

	f.close();
}


This is my employee file 
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#include "employee.h"

using namespace std;

Employee::Employee() {
	ma_so_ = "";//id
	ten_ = "";//Name
	ngay_sinh_ = "";//Birth
	email_ = "";
	dien_thoai_ = "";//Phone
	dia_chi_ = "";//Address
	luong_co_ban_ = 0.0;//Salary

}

Employee::~Employee() {

}

void Employee::NhapThongTin() {
	cin.ignore();
	cout << "Nhap thong tin mot nhan vien moi\n";
	cout << "Ma so:";
	getline(cin, ma_so_);
	cout << "Ho & Ten:";
	getline(cin, ten_);
	cout << "Ngay sinh:";
	getline(cin, ngay_sinh_);
	cout << "Email:";
	getline(cin, email_);
	cout << "Dien thoai:";
	getline(cin, dien_thoai_);
	cout << "Dia chi:";
	getline(cin, dia_chi_);
	cout << "Luong co ban:";
	cin >> luong_co_ban_;
}

void Employee::XuatThongTin() {
	cout << "Ma so: " << ma_so_ << endl;
	cout << "Ho & Ten: " << ten_ << endl;
	cout << "Ngay sinh: " << ngay_sinh_ << endl;
	cout << "Email: " << email_ << endl;
	cout << "Dien thoai: " << dien_thoai_ << endl;
	cout << "Dia chi: " << dia_chi_ << endl;
}

float Employee::TinhLuong() {
	return luong_co_ban_;
}

const std::string& Employee::getDiaChi() const {
	return dia_chi_;
}

void Employee::setDiaChi(const std::string& diaChi) {
	dia_chi_ = diaChi;
}

const std::string& Employee::getDienThoai() const {
	return dien_thoai_;
}

void Employee::setDienThoai(const std::string& dienThoai) {
	dien_thoai_ = dienThoai;
}

const std::string& Employee::getEmail() const {
	return email_;
}

void Employee::setEmail(const std::string& email) {
	email_ = email;
}

float Employee::getLuongCoBan() const {
	return luong_co_ban_;
}

void Employee::setLuongCoBan(float luongCoBan) {
	luong_co_ban_ = luongCoBan;
}

const std::string& Employee::getMaSo() const {
	return ma_so_;
}

void Employee::setMaSo(const std::string& maSo) {
	ma_so_ = maSo;
}

const std::string& Employee::getNgaySinh() const {
	return ngay_sinh_;
}

void Employee::setNgaySinh(const std::string& ngaySinh) {
	ngay_sinh_ = ngaySinh;
}

const std::string& Employee::getTen() const {
	return ten_;
}

void Employee::setTen(const std::string& ten) {
	ten_ = ten;
}


and my Manager file 
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#include "manager.h"

using namespace std;

Manager::Manager() :
		Employee() {
	chuc_vu_ = "";//roll
	he_so_chuc_vu_ = 0.0;//roll hierarchy
	thuong_ = 0.0;
}

Manager::~Manager() {

}

void Manager::NhapThongTin() {
	Employee::NhapThongTin();
	cin.ignore();
	cout << "Chuc vu:";
	getline(cin, chuc_vu_);
	cout << "He so chu vu:";
	cin >> he_so_chuc_vu_;
	cout << "Thuong:";
	cin >> thuong_;
}

float Manager::TinhLuong() {
	return luong_co_ban_ + luong_co_ban_ * he_so_chuc_vu_ + thuong_;
}

void Manager::XuatThongTin() {
	Employee::XuatThongTin();
	cout << "Chuc vu: " << chuc_vu_ << endl;
	cout << "Luong: " << TinhLuong() << endl;
}

const std::string& Manager::getChucVu() const {
	return chuc_vu_;
}

void Manager::setChucVu(const std::string& chucVu) {
	chuc_vu_ = chucVu;
}

float Manager::getHeSoChucVu() const {
	return he_so_chuc_vu_;
}

void Manager::setHeSoChucVu(float heSoChucVu) {
	he_so_chuc_vu_ = heSoChucVu;
}

float Manager::getThuong() const {
	return thuong_;
}

void Manager::setThuong(float thuong) {
	thuong_ = thuong;
}


And my list file 
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#include "list.h"
#include "employee.h"

template <class T>
List<T>::List() {
	index = 0;
}

template <typename T>
List<T>::~List() {

}

template<class T>
void List<T>::add(T const& item) {
	elements_[index] = item;
	index++;
}

template<class T>
T List<T>::get(int pos) {
	int n = sizeof(elements_) / sizeof(elements_[0]);
	if (pos < 0 || pos >= n)
		throw std::out_of_range("error");
	return elements_[pos];
}

template<class T>
int List<T>::size() {
	if (index == 0)
	{
		return 0;
	}
	else
	{
		return index;
	}
}
Last edited on
salem c (3700)
Why is this in the jobs section?

> f.open("employee.txt", std::ios_base::binary | std::ios_base::app);
Get rid of this, because you've already opened the file.

> f.write(reinterpret_cast<char*>(&list), sizeof(list));
Get rid of this, because it's wrong in so many ways.
Just stick to the f << approach.
PoorBoiz (38)
#salem c
You're right. It works perfectly, but could you explain the second one for me? Why that cast matter?
Last edited on
salem c (3700)
Well the first thing you need to do is convince yourself that sizeof(list) is a constant, and has absolutely no bearing on the number of elements in the list.

The only thing you can reliably use f.write with are POD types.
https://en.cppreference.com/w/cpp/named_req/PODType

> Why that cast matter?
Because C++ doesn't have a void* like C does that just means "here are some bytes".
PoorBoiz (38)
#salem c
Thanks a lot!
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