Object Vector C++

Question

I am trying to learn more about vectors and store objects in it. I am reading data from the txt file. I cannot see what mistake I'm making that it does not work.

Here are my main methods

void Reader::readFoodFile() {
    string name;
    int cal, cost;
    ifstream file;
    file.open("food.txt");
    while (file >> name >> cal >> cost) {
        Food f(name, cal, cost);
        foodStorage.push_back(f); 

    } 
}
void Reader::getStorage() {
    for (unsigned int i = 0; i < foodStorage.size(); i++) {
        cout << foodStorage[i].getName();
    }
}

And here is my Food constructor:

Food::Food(string newName, int newCalories, int newCost) {
    this->name = newName;
    this->calories = newCalories;
    this->cost = newCost;
}

In my main.cpp file I'm just creating the object Reader(no constructor now) and call the methods.

int main(int argc, char** argv) {

        Reader reader;
        reader.readFoodFile();
        reader.getStorage();
}

I want to populate the Vector with objects that take data from the txt file and then print it out(for now).

Any suggestions?

edit; my .txt file layout is

apple 4 2
strawberry 2 3
carrot 2 2

Here is my Food.h and Reader.h

#ifndef FOOD_H
#define FOOD_H

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

using namespace std;

class Food {
public:
    Food();
    Food(string, int, int);
    Food(const Food& orig);
    virtual ~Food();
    string getName();
    int getCalories();
    int getCost();
    void setCost(int);
    void setCalories(int);
    void setName(string);
    int calories, cost;
    string name;
private:

};

#endif  /* FOOD_H */`

and Reader.h
`#ifndef READER_H
#define READER_H
#include <string> 
#include <fstream>
#include <iostream>
#include <vector>
#include "Food.h"

using namespace std;

class Reader {
public:
    Reader();
    Reader(const Reader& orig);
    virtual ~Reader();

    void readFoodFile();
    void getStorage();
    vector<Food> foodStorage;

private:

};

#endif  /* READER_H */

When I try to call getStorage() I get no output, just a blank line. — ChrisA, May 02 '13 at 00:16
I'm using a standard Netbeans Debugger. Also, I'm looking at the console output. — ChrisA, May 02 '13 at 00:26
Try adding '<< endl;' to the end of your cout line, as it might not be flushing stdout. — Stephan van den Heuvel, May 02 '13 at 00:30
I would set a breakpoint in the debugger on this line: foodStorage.push_back(f); Just to make sure you're reading your text file properly — Scott Jones, May 02 '13 at 00:32
your code worked for me, the problem is somewhere in the code u did not show us. — yngccc, May 02 '13 at 00:33
@yngum There really isn't much more code to be shown really... I'm checking my headers and everything looks fine. — ChrisA, May 02 '13 at 00:37
If you are making a copy make sure your copy constructors are correct. — Captain Obvlious, May 02 '13 at 01:06
Are you sure the file is being opened? use `ifstream::is_open()` to check. — Maria Ines Parnisari, May 02 '13 at 01:08
Sorry, what do you mean? My 'Food' constructor is in the topic, how would I go about making sure it is correct? Yes, I can add 'cout << name' in my while{} loop and it would return proper values, also debugged and check it. — ChrisA, May 02 '13 at 01:09
`string Food::getName() { return name; }` is implemented and public. I can't retrieve anything, either by calling getX or by calling the variable directly. The Vector seems to lack any values when I call `getStorage()`, but has the size of 3. — ChrisA, May 02 '13 at 01:16
So, when you run it in the debuger , name it's self has a value? in the getName() function... ? And are you compiling this as C++ 98, or C++ 11? — johnathan, May 02 '13 at 01:46
can you please just paste the entire files you are using? that may help people to see what you are missing. — Bill, May 02 '13 at 01:54

score 0 · Answer 1 · answered May 02 '13 at 02:02

I'm guessing your exe is running with a different relative path to the one you expect. Check that file.good() is true after you call file.open(). This problem is common when the programming IDE (e.g. Visual Studio) runs the exe with a different working folder to where the exe is being written.

Bill · Accepted Answer · 2013-05-02T02:18:38.390

I just compiled your code and it works fine for me....I used g++.... Things you need to fix ..

get rid of the constructors you have in .h file and not defined in .cpp
give an implementation of getName.

The following is my code:

food.h

#ifndef FOOD_H 
#define FOOD_H

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

using namespace std;

class Food { public:
    //Food();
    Food(string, int, int);
    //Food(const Food& orig);
    //virtual ~Food();
    string getName();
    int getCalories();
    int getCost();
    void setCost(int);
    void setCalories(int);
    void setName(string);
    int calories, cost;
    string name; private:

};

#endif

food.cpp

#include<iostream> 
#include<string> 
#include "food.h" 
using namespace std; 
 Food::Food(string newName, int newCalories, int newCost) {
    this->name = newName;
    this->calories = newCalories;
    this->cost = newCost; } string Food::getName() {
        return name; }

reader.h

#ifndef READER_H 
#define READER_H 
#include <string> 
#include <fstream> 
#include <iostream> 
#include <vector> 
#include "food.h"

    using namespace std;

    class Reader { public:
        //Reader();
        //Reader(const Reader& orig);
        //virtual ~Reader();

        void readFoodFile();
        void getStorage();
        vector<Food> foodStorage;

    private:

    };

    #endif

reader.cpp

#include <iostream> 
#include "reader.h"

using namespace std; void Reader::readFoodFile() {
    string name;
    int cal, cost;
    ifstream file;
    file.open("food.txt");
    while (file >> name >> cal >> cost) {
        Food f(name, cal, cost);
        foodStorage.push_back(f);

    } } void Reader::getStorage() {
    for (unsigned int i = 0; i < foodStorage.size(); i++) {
        cout << foodStorage[i].getName();
    } }

main.cpp

#include<iostream>
#include<fstream>
#include "food.h"
#include "reader.h"

using namespace std;

int main(int argc, char** argv) {
        Reader reader;
        reader.readFoodFile();
        reader.getStorage();
}

I compiled using -- g++ main.cpp reader.cpp food.cpp

and the output I get -- applestrawberrycarrots

So, I am not sure what you are missing....hope this helps

I did not add std::endl .. if you do add that where you have std::cout then each item will be on their own line. Also, you should close the stream after you are done using it.

Thank you very much. The removal of ` Food(); Food(const Food& orig); virtual ~Food();` Helped me to solve the problem. I'll keep that in mind for the future! — ChrisA, May 02 '13 at 10:29
Glad it helped...whenever you define a constructor in `.h` but dnt give a definition, c++ will complain `undefined reference` as it does not understand how to instantiate the constructor (http://stackoverflow.com/questions/5393293/undefined-reference-to-classclass) — Bill, May 02 '13 at 12:26

Object Vector C++

2 Answers2