Answer to Question #298707 in C++ for mak

Question

Student information Window

The data should be saved in a file.

The student record may be deleted.

The student record may be searched based on the ID provided.

The student record may be updated in case if its phone no or house address changes.

Answer 1

#include <iostream>
#include <vector>
#include <fstream>
int next_id = 0;
class Student
{
public:
	Student();
	~Student();


	int id=0;
	std::string name="";
	std::string surname="";
	std::string city="";
	std::string street="";
	std::string phone_number = "";
	int building = 0;
	int house = 0;


	void input_info()
	{
		std::cout << "Enter name : ";
		std::cin >> name;
		std::cout << "Enter surname : ";
		std::cin >> surname;
		std::cout << "Enter city : ";
		std::cin >> city;
		std::cout << "Enter street : ";
		std::cin >> street;
		std::cout << "Enter building : ";
		std::cin >> building;
		std::cout << "Enter house : ";
		std::cin >> house;
		std::cout << "Enter phone number : ";
		std::cin >> phone_number;
	}
	void output_info()
	{
		std::cout << id << "." << name << " " << surname << " , " << city << " " << " " << building << " " << house << " , " << phone_number << std::endl;
	}
};


Student::Student()
{
	id = next_id;
	next_id++;
}


Student::~Student()
{
}


void save_to_file(std::vector<Student> & students, std::string file_name)
{
	std::ofstream file(file_name);
	file << students.size() << '\n';
	for (auto&& it : students)
	{
		file << it.id << " " << it.name << " " << it.surname << " " << it.phone_number << " " << it.city << " " << it.street << " " << it.house << " " << it.building << " " << it.house << "\n";
	}
	file.close();
}
void load_from_file(std::vector<Student>& students, std::string file_name)
{
	std::ifstream file(file_name);
	Student tmp;
	int size = 0;
	file >> size;
	students.resize(size);
	for (int i=0;i<size;i++)
	{
		file >> tmp.id >> tmp.name >>  tmp.surname >>  tmp.phone_number >>  tmp.city >>  tmp.street >>  tmp.house >>  tmp.building >>  tmp.house;
		students[i] = tmp;
	}
	
	file.close();
}


int main() 
{
	std::vector<Student> students;
	load_from_file(students, "students.txt");
	int answer = 0;
	while (1)
	{
		answer = 0;
		std::cout << "1.Add student\n2.Update student\n3.Save info\n4.Print students\n5.Exit\nEnter value : ";
		std::cin >> answer;
		if (answer == 1)
		{
			Student tmp;
			tmp.input_info();
			students.push_back(tmp);
		}
		else if (answer == 2)
		{
			bool is_found = 0;
			Student tmp;
			int id = 0;
			std::cout << "Enter id : ";
			std::cin >> id;
			for (auto&& it : students)
			{
				if (it.id == id)
				{
					is_found = 1;
					tmp.input_info();
					it = tmp;
					break;
				}
			}
			if (!is_found)
			{
				std::cout << "There is no student with such id\n";
			}
		}
		else if (answer == 3)
		{
			save_to_file(students, "students.txt");
			std::cout << "Saved\n";
		}
		else if (answer == 4)
		{
			for (auto&& it : students)
			{
				it.output_info();
			}
		}
		else if (answer == 5)
		{
			exit(0);
		}
	}


	system("pause");
	return 0;
}