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Cannot get a string from user input stream in first loop of entry

Shishykish (140)
Hello,

I have written the following code below. The outcome I would like to achieve is to be able to get data from a user input stream about city information and to output this stream to create a text file.

Whilst I am able to successfully input and output to a text file, when my program prompts the user for a city name, it skips it and just goes for population and name of mayor. 

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#include <iostream>
#include <fstream>
#include <cstdlib>
#include <string>
#include <iomanip>
#include <math.h>

using namespace std;

const int columns = 3;

void City_Data_Inputtofile(string[][columns], int);
//void City_Data_View(string[][columns], int);

void City_Data_Inputtofile (string City_Data[][columns], int NO_OF_CITIES)
{

    ofstream outFile;
    string City_Name, Population, Name_of_Mayor;

    outFile.open("City_Information.txt");

    if (outFile.fail())
    {
        cout << "File failed to open"<<endl;
    }

    cout << "City Name" << setw(20) << "Population" << setw(20) << "Name of Mayor" << endl;
    outFile << "City Name" << setw(20) << "Population" << setw(20) << "Name of Mayor" << endl;

    for (int i = 0; i < NO_OF_CITIES; i++)
    {
            cout << "Enter the name of the city" << endl;
            getline(cin,City_Name);
            City_Data[i][0] = City_Name;
            outFile << City_Data[i][0] << setw(20);
            cout << endl;

            cout << "Enter the population of the city" <<endl;
            getline(cin,Population);
            City_Data[i][1] = Population;
            outFile << City_Data[i][0] << setw(20);
            cout << endl;

            cout << "Enter the Name of the Mayor" <<endl;
            getline(cin,Name_of_Mayor);
            City_Data[i][2] = Name_of_Mayor;
            outFile << City_Data[i][2] << setw(20);

            outFile << endl;

            cout << endl;
    }


    for (int i = 0; i < NO_OF_CITIES; i++)
    {
        cout << "Name of City"<< endl;
        cout << City_Data[i][0] << endl;

        cout << "Population" <<endl;
        cout << City_Data[i][1] << endl;

        cout << "Name of Mayor" <<endl;
        cout << City_Data[i][2] <<endl;
    }

    outFile.close();

    return;
}

/*void City_Data_Output(string City_Data[][columns], int NO_OF_CITIES)
{

}*/

int main()
{

int no_of_cities;

cout << "This program will make a file to story city information" << endl;
cout << "Enter the number of cities that you would like to store in this file" <<endl;

cin >> no_of_cities;

string CITY_DATA [no_of_cities][columns];

City_Data_Inputtofile(CITY_DATA, no_of_cities);

//City_Data_Output(CITY_DATA, no_of_cities);

return 0;

}
lastchance (6980)
Actually, I don't know! However, I have some qualms about what you are doing in lines 87 and 89. The size of array CITY_DATA is NOT known at compile time: I think you should be dynamically allocating it, using new. (Alternatively, use a container from the Standard Template Library, but that may be a bit advanced and/or overkill.)

When I commented out your line 87 and set a number of cities explicitly in line 82 then the code seemed to accept data OK. In this case the size of array CITY_DATA would have been known at compile time.
Shishykish (140)
Dear Last Chance,

I did that and it worked perfectly! But I even tried setting up a seperate function to set up the no of cities.

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#include <iostream>
#include <fstream>
#include <cstdlib>
#include <string>
#include <iomanip>
#include <math.h>

using namespace std;

const int columns = 3;

void City_Data_Inputtofile(string[][columns], int);
//void City_Data_View(string[][columns], int);

void City_Data_Inputtofile (string City_Data[][columns], int NO_OF_CITIES)
{

    ofstream outFile;
    string City_Name[NO_OF_CITIES], Population[NO_OF_CITIES], Name_of_Mayor[NO_OF_CITIES];

    outFile.open("City_Information.txt");

    if (outFile.fail())
    {
        cout << "File failed to open"<<endl;
    }

    cout << "City Name" << setw(20) << "Population" << setw(20) << "Name of Mayor" << endl;
    outFile << "City Name" << setw(20) << "Population" << setw(20) << "Name of Mayor" << endl;

    for (int i = 0; i < NO_OF_CITIES; i++)
    {
            cout << "Enter the name of the city" << endl;
            getline(cin,City_Name[i]);
            City_Data[i][0] = City_Name[i];
            outFile << City_Data[i][0] << setw(20);
            cout << endl;

            cout << "Enter the population of the city" <<endl;
            getline(cin,Population[i]);
            City_Data[i][1] = Population[i];
            outFile << City_Data[i][0] << setw(20);
            cout << endl;

            cout << "Enter the Name of the Mayor" <<endl;
            getline(cin,Name_of_Mayor[i]);
            City_Data[i][2] = Name_of_Mayor[i];
            outFile << City_Data[i][2] << setw(20);

            outFile << endl;

            cout << endl;
    }

    for (int i = 0; i < NO_OF_CITIES; i++)
    {
        cout << "Name of City"<< endl;
        cout << City_Data[i][0] << endl;

        cout << "Population" <<endl;
        cout << City_Data[i][1] << endl;

        cout << "Name of Mayor" <<endl;
        cout << City_Data[i][2] <<endl;
    }

    outFile.close();

    return;
}

/*void City_Data_Output(string City_Data[][columns], int NO_OF_CITIES)
{

}*/

int main()
{

int no_of_cities = 2;

cout << "This program will make a file to story city information" << endl;
cout << "Enter the number of cities that you would like to store in this file" <<endl;

//cin >> no_of_cities;

string CITY_DATA [no_of_cities][columns];

City_Data_Inputtofile(CITY_DATA, no_of_cities);

//City_Data_Output(CITY_DATA, no_of_cities);

return 0;

}


I decided to break it down and make a function where the you can set the number of cities before the input to file function was called. I also set the no_of_cities variable as a global one.

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#include <iostream>
#include <fstream>
#include <cstdlib>
#include <string>
#include <iomanip>
#include <math.h>

using namespace std;

const int columns = 3;
extern int no_of_cities = 0;

void City_Data_Inputtofile(string[][columns]);
int set_no_of_cities (int);
//void City_Data_View(string[][columns], int);

int set_no_of_cities(int CITY_NUMBERS)
{
    cout << "Enter the number of cities that you would like to store in this file" <<endl;

    cin >> no_of_cities;

    return 0;
}

void City_Data_Inputtofile (string City_Data[][columns])
{

    ofstream outFile;
    string City_Name[no_of_cities], Population[no_of_cities], Name_of_Mayor[no_of_cities];

    outFile.open("City_Information.txt");

    if (outFile.fail())
    {
        cout << "File failed to open"<<endl;
    }

    cout    << "City Name" << setw(20) << "Population" << setw(20) << "Name of Mayor" << endl;
    outFile << "City Name" << setw(20) << "Population" << setw(20) << "Name of Mayor" << endl;

    for (int i = 0; i < no_of_cities; i++)
    {
            cout << "Enter the name of the city" << endl;
            getline(cin,City_Name[i]);
            City_Data[i][0] = City_Name[i];
            outFile << City_Data[i][0] << setw(20);
            cout << endl;

            cout << "Enter the population of the city" <<endl;
            getline(cin,Population[i]);
            City_Data[i][1] = Population[i];
            outFile << City_Data[i][1] << setw(20);
            cout << endl;

            cout << "Enter the Name of the Mayor" <<endl;
            getline(cin,Name_of_Mayor[i]);
            City_Data[i][2] = Name_of_Mayor[i];
            outFile << City_Data[i][2] << setw(20);

            outFile << endl;

            cout << endl;
    }

    cout << "Here is the data you entered" << endl;

    for (int i = 0; i < no_of_cities; i++)
    {
        cout << "Name of City"<< endl;
        cout << City_Data[i][0] << endl;

        cout << "Population" <<endl;
        cout << City_Data[i][1] << endl;

        cout << "Name of Mayor" <<endl;
        cout << City_Data[i][2] <<endl;
    }

    outFile.close();

    return;
}

/*void City_Data_Output(string City_Data[][columns], int NO_OF_CITIES)
{

}*/

int main()
{

cout << "This program will make a file to story city information" << endl;

string CITY_DATA [no_of_cities][columns];

set_no_of_cities(no_of_cities);
City_Data_Inputtofile(CITY_DATA);

//City_Data_Output(CITY_DATA, no_of_cities);

return 0;

}


I get the following with the program refusing to work :(


This program will make a file to story city information
Enter the number of cities that you would like to store in this file
2
City Name          Population       Name of Mayor
Enter the name of the city

Process returned -1073741819 (0xC0000005)   execution time : 3.562 s
Press any key to continue.
Last edited on
lastchance (6980)
The number of cities, which you are using to set the size of your array, is NOT known at compile time - however you do it you are inputting it during RUN time (in line 97). Array CITY_DATA needs to be dynamically allocated.



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