Trying to input a file and storing the data in a vector

[kostomberov]

Hello everyone! I am trying to store the data of a file into a vector of type Ingredients*. I would really appreciate it if you could help me. The project has a three-level hierarchy of classes with a base class Ingredients. I can paste the constructors and the source of them too. Thank you in advance! Sorry for my English :)

  bool readFile(vector<Ingredients*> inventory) {
	ifstream inFile("Data.txt");
	if (!inFile)
		return false; // If the object was unable to open the file
	else {
		Ingredients* temp;
		/*string id;
		string line;
		string name;*/
		//int quantity;
		while (inFile >> temp->quantity) {
			inFile.ignore();
			getline(inFile, temp->name);
			getline(inFile, temp->id);
			inventory.push_back(temp);
		}

		inFile.close();
		return true;
	}
}

int main() {
	vector<Ingredients*> v;
	readFile(v);
	if (!readFile(v))
		return 1;
	else {
		for (int i = 0; i < v.size(); ++i) {
			cout << v[i]->getType() << " - " << v[i]->getId() << " - " << v[i]->getFoodType() << " - " << v[i]->getName()
				<< " - " << v[i]->getQuantity() << " - " << v[i]->getExpirationDate() << endl;
		}
	}


	return 0;
}

[jlb]

First why the Ingredients*? Why not just an Ingredient?

Second where are you allocating/de-allocating memory for that pointer?

Third do you realize that the vector<> in the readFile() function is a copy and all changes made to that vector inside the function is lost when the function returns? Perhaps you should be passing the vector by reference?

[kostomberov]

Hi, thank you for the reply! I am now passing it as a reference but I am not sure how to get the code to output the vector. I saw a similar code on another post here and tried to change it for my purpose. I would appreciate it if you could help a bit. It currently starts but doesn't output anything.

bool readFile(vector<Ingredients> &inventory) {
	ifstream inFile("Data.txt");
	if (!inFile)
		return false; // If the object was unable to open the file
	else {
		Ingredients temp;
		while (inFile >> temp.quantity) {
			inFile.ignore();
			getline(inFile, temp.name);
			getline(inFile, temp.id);
			inventory.push_back(temp);
		}

		inFile.close();
		return true;
	}
}

int main() {
	vector<Ingredients> v;
	if (!readFile(v))
		return 1;
	else {
		for (int i = 0; i < v.size(); ++i) {
			cout << v[i].getType() << " - " << v[i].getId() << " - " << v[i].getFoodType() << " - " << v[i].getName()
				<< " - " << v[i].getQuantity() << " - " << v[i].getExpirationDate() << endl;
		}
	}


	return 0;
}

[jlb]

It would help if you posted a complete program and the contents of your input file.

Have you tried to run the program with your debugger? With the debugger you should be able to single step through the program and watching the variables as you single step.

[kostomberov]

I will try with the debugger now but here is the program if you like to take a look.


txt file:
AF
1
Pork
Meat
5
14/05/2020
PB
2
banana
4
fruit
15/06/2020
yes
AF
3
Veal
Meat
5
13/04/2021

#pragma once
#include <iostream>
using namespace std;

class Ingredients {
public:
	int quantity;
//protected:
	string type;
	string id;
	string name;
	string foodType;
	string expirationDate;
public:
	string getFoodType();
	int getQuantity();
	string getId();
	string getName();
	string getType();
	string getExpirationDate();

	Ingredients() {}

	Ingredients(string type, string id, string name, int quantity, string foodType, string expirationDate);

};


#include <iostream>
#include "Ingredients.h"
using namespace std;

Ingredients::Ingredients(string type, string id, string name, int quantity, string foodType, string expirationDate) :
	type(type),
	id(id),
	name(name),
	quantity(quantity),
	foodType(foodType),
	expirationDate(expirationDate) 
{
}

string Ingredients::getType() {
	return type;
}

string Ingredients::getExpirationDate() {
	return expirationDate;
}

string Ingredients::getId() {
	return id;
}

string Ingredients::getName() {
	return name;
}

int Ingredients::getQuantity() {
	return quantity;
}


string Ingredients::getFoodType() {
	return foodType;
}

#pragma once
#include <iostream>
#include "Ingredients.h"
using namespace std;

class AnimalFoods : public Ingredients {
public:
	string animal;
	string getAnimal();

	AnimalFoods(string type, string id, string name, int quantity, string foodType, string expirationDate, string animal);
};


#include <iostream>
#include "AnimalFoods.h"
using namespace std;

string AnimalFoods::getAnimal() {
	return animal;
}

AnimalFoods::AnimalFoods(string type, string id, string name, int quantity, string foodType, string expirationDate, string animal) :
	Ingredients( type,  id,  name,  quantity,  foodType,  expirationDate),
	animal(animal)
{
	
}


#pragma once
#include <iostream>
#include "Ingredients.h"
using namespace std;

class PlantBasedFoods : public Ingredients {
public:
	string seasonal;
	string isSeasonal();

	PlantBasedFoods(string type, string id, string name, int quantity, string foodType, string expirationDate, string seasonal);
};

#include <iostream>
#include "PlantBasedFoods.h"
using namespace std;

string PlantBasedFoods::isSeasonal() {
	if (seasonal == "Y") {
		return "seasonal";
	}
	return "not seasonal";
}

PlantBasedFoods::PlantBasedFoods(string type, string id, string name, int quantity, string foodType, string expirationDate, string seasonal) :
	Ingredients(type, id, name, quantity, foodType, expirationDate),
	seasonal(seasonal)
{

}

#pragma once
#include <iostream>
using namespace std;

class Inventory {
public:
	string number;
	string getInventoryNum();
};

#include <iostream>
#include <vector>
#include "Inventory.h"
#include "Ingredients.h"
#include "PlantBasedFoods.h"
#include "AnimalFoods.h"
#include "Fruits.h"
#include "Vegetables.h"
#include "Meat.h"
#include "Dairy.h"
#include <iterator>
#include <algorithm>
#include <fstream>
#include <string>
using namespace std;

string Inventory::getInventoryNum() {
	return number;
}

//merge function
void merge(vector<Ingredients*>& a, vector<Ingredients*>& tmpArr, int l, int r, int rEnd) {
	int lEnd = r - 1;
	int tmpPos = l;
	int numElements = rEnd - l + 1;

	while (l <= lEnd && r <= rEnd)
		if (a[l]->quantity <= a[r]->quantity)
			tmpArr[tmpPos++] = a[l++];
		else
			tmpArr[tmpPos++] = a[r++];

	while (l <= lEnd)
		tmpArr[tmpPos++] = a[l++];

	while (r <= rEnd)
		tmpArr[tmpPos++] = a[r++];

	for (int i = 0; i < numElements; i++, rEnd--)
		a[rEnd] = tmpArr[rEnd];
}

//mergesort function
void mergeSort(vector<Ingredients*>& a, vector<Ingredients*>& tmpArr, int l, int r)
{
	if (l < r) {
		int center = (l + r) / 2;
		mergeSort(a, tmpArr, l, center);
		mergeSort(a, tmpArr, center + 1, r);
		merge(a, tmpArr, l, center + 1, r);
	}
}

void mergeSort(vector<Ingredients*>& a)
{
	vector<Ingredients*> tmpArr(a.size());
	mergeSort(a, tmpArr, 0, a.size() - 1);
}


void PrintVector(vector<Ingredients*> v) {

	for (int i = 0; i < v.size(); ++i) {
		cout << v[i]->getType() << " - " << v[i]->getId() << " - " << v[i]->getFoodType() << " - " << v[i]->getName()
			<< " - " << v[i]->getQuantity() << " - " << v[i]->getExpirationDate() << endl;
	}
}
bool readFile(vector<Ingredients> &inventory) {
	ifstream inFile("Data.txt");
	if (!inFile)
		return false; // If the object was unable to open the file
	else {
		string type, id, name, foodtype, expirationdate;
		int quantity;	
		while (inFile >> quantity) {
			inFile.ignore();
			getline(inFile, type);
			getline(inFile, id);
			getline(inFile, name);
			getline(inFile, foodtype);
			getline(inFile, expirationdate);
			
			Ingredients foo;
			foo.getId();
			foo.getName();
			foo.getFoodType();
			foo.getExpirationDate();
			foo.getQuantity();
			inventory.push_back(foo);
		}
		inFile.close();
		return true;
	}
}

int main() {
	vector<Ingredients> v;
	if (!readFile(v))
		return 1;
	else {
		for (int i = 0; i < v.size(); ++i) {
			cout << v[i].getType() << " - " << v[i].getId() << " - " << v[i].getFoodType() << " - " << v[i].getName()
				<< " - " << v[i].getQuantity() << " - " << v[i].getExpirationDate() << endl;
		}
	}


	return 0;
}

[Peter87]

The first thing you try to read is the quantity, an int, but the first row contains "AF" which is not an integer value (unless you interpret it as hex).

[kostomberov]

after I changed the input to start with a int I managed to get output but it is not human-readable

- - - - -858993460 -
- - - - -858993460 -

[seeplus]

AF
1
Pork
Meat
5
14/05/2020
PB
2
banana
4
fruit
15/06/2020
yes
AF
3
Veal
Meat
5
13/04/2021

That format is inconsistent. Sometimes there is a number between name and foodtype and sometimes there isn't. The format of the data file needs to be consistent for each entry - otherwise the file read will not work properly.

[kostomberov]

I have changed the txt to be consistent

12
AF
3445
Pork
Meat
12/02/2019
14
PB
1221
Apple
Fruit
13/03/2020
15
AF
2342
Veal
Meat
13/12/2020

But now the output is not human-readable:
- - - - -858993460 -
- - - - -858993460 -
- - - - -858993460 -

At least now the rows are three as supposed to

[seeplus]

When coding, it's better to code in small parts and compile/test before moving on to code the next part. This means that you don't write a lot of code then comer to compile/test and find loads of problems.

As starter code to read and display the file consider:

#include <string>
#include <iostream>
#include <fstream>
#include <vector>

class Ingredients {
private:
	int quantity {};
	std::string type;
	std::string id;
	std::string name;
	std::string foodType;
	std::string expirationDate;

public:
	std::string getFoodType() const;
	int getQuantity()const ;
	std::string getId() const;
	std::string getName() const;
	std::string getType() const;
	std::string getExpirationDate() const;

	Ingredients() {}

	Ingredients(const std::string& type, const std::string& id, const std::string& name, int quantity, const std::string& foodType, const std::string& expirationDate);

	friend std::istream& operator>>(std::istream& inFile, Ingredients& i);
};

std::istream& operator>>(std::istream& inFile, Ingredients& i) {
	if (inFile) {
		inFile >> i.quantity >> std::ws;
		std::getline(inFile, i.type);
		std::getline(inFile, i.id);
		std::getline(inFile, i.name);
		std::getline(inFile, i.foodType);
		std::getline(inFile, i.expirationDate);
	}

	return inFile;
}

std::ostream& operator<<(std::ostream& os, const Ingredients& e) {
		os << e.getType() << " - " << e.getId() << " - " << e.getFoodType() << " - " << e.getName()
		<< " - " << e.getQuantity() << " - " << e.getExpirationDate();
}

Ingredients::Ingredients(const std::string& type, const std::string& id, const std::string& name, int quantity, const std::string& foodType, const std::string& expirationDate) :
	type(type), id(id), name(name), quantity(quantity), foodType(foodType), expirationDate(expirationDate) { }

std::string Ingredients::getType() const {
	return type;
}

std::string Ingredients::getExpirationDate() const {
	return expirationDate;
}

std::string Ingredients::getId() const {
	return id;
}

std::string Ingredients::getName() const {
	return name;
}

int Ingredients::getQuantity() const {
	return quantity;
}

std::string Ingredients::getFoodType() const {
	return foodType;
}

bool readFile(std::vector<Ingredients>& inventory) {
	std::ifstream inFile("Data.txt");

	if (!inFile)
		return false;

	for (Ingredients ing; inFile >> ing; inventory.push_back(ing));
	return true;
}

void printVector(const std::vector<Ingredients>& inventory) {
	for (const auto& e : inventory)
		std::cout << e << '\n';
}

int main() {
	std::vector<Ingredients> v;

	if (!readFile(v))
		return (std::cout << "Cannot open file\n"), 1;

	printVector(v);
}

AF - 3445 - Meat - Pork - 12 - 12/02/2019
PB - 1221 - Fruit - Apple - 14 - 13/03/2020
AF - 2342 - Meat - Veal - 15 - 13/12/2020

[Peter87]

Those unreadable numbers are probably the result of using the default constructor when creating foo which leaves all the member variables uninitialized. Either pass the values to the constructor or read the values directly into the member variables like you did earlier and like seeplus did in his latest post (if you want the member variables to be private or protected you will have to go with the pass-values-to-constructor approach).

[kostomberov]

Thank you! I really appreciate your help. I have now added the other classes as well.