File input and output

[Hypnotik]

Hey all. I am working with a file input/output program. The program is take input from a file, manipulate the info, and then output the info to another file.

The program takes the input just fine, although I am unable to manipulate the info (hours worked* payrate). I have all arrays set as character arrays, I believe that might be the problem.

[mac11]

How are you trying to manipulate your data. Manipulating character arrays is quite common. What specific methods/functions are you trying that aren't working?

[Savage]

Hey all. I am working with a file input/output program. The program is take input from a file, manipulate the info, and then output the info to another file.

The program takes the input just fine, although I am unable to manipulate the info (hours worked* payrate). I have all arrays set as character arrays, I believe that might be the problem.

That's good,u know to determine where the problem is and this is first and(probably) ur hardest step.Can u please post that troubleshoting code,so that we can help u solve it?

And it would be nice if u please read posting guidelines if u haven't already,they will help u to get ur answer a way more faster..

:D

Savage

[Hypnotik]

Hey Savage, sorry for not posting the code right away. I realized I had taken out some info from the program while troubleshooting, and I was on my way out the door.

Here is the code:

 
#include <iostream>
#include <fstream>
#include <iomanip>
using namespace std;
void main()
{
    int i=1,r=0;
    char FirstName[10]={0}, LastName[9]={0}, IDNumber[10]={0},PayRate[10]={0},HoursWorked[12]={0},TotalPay[10]={0};
    ifstream ifp;
    ofstream ofp;
    ifp.open("c:\\Documents and Settings\\Jeff Young\\Desktop\\Lab14.in");
    ofp.open("c:\\Pay.out");
    while (ifp>>FirstName>>LastName>>IDNumber>>HoursWorked>>PayRate)
    {
        if (HoursWorked<=40)
            TotalPay=HoursWorked*PayRate;
        else
            TotalPay=(40*PayRate)+(HoursWorked-40)*PayRate*1.5;
    }
//    cout<<setw(10)<<FirstName<<"   "<<setw(10)<<LastName<<"   "<<setw(10)<<IDNumber<<"    "<<setw(10)<<HoursWorked<<"  "<<setw(10)<<PayRate<<"   "<<endl;
    cout<<setw(10)<<LastName<<"    "<<setw(10)<<IDNumber<<"   "<<setw(10)<<TotalPay<<endl;
}
 
 

Thanks alot.

J

[Savage]

Hey Savage, sorry for not posting the code right away. I realized I had taken out some info from the program while troubleshooting, and I was on my way out the door.

Here is the code:

 
#include <iostream>
#include <fstream>
#include <iomanip>
using namespace std;
void main()
{
    int i=1,r=0;
    char FirstName[10]={0}, LastName[9]={0}, IDNumber[10]={0},PayRate[10]={0},HoursWorked[12]={0},TotalPay[10]={0};
    ifstream ifp;
    ofstream ofp;
    ifp.open("c:\\Documents and Settings\\Jeff Young\\Desktop\\Lab14.in");
    ofp.open("c:\\Pay.out");
    while (ifp>>FirstName>>LastName>>IDNumber>>HoursWorked>>PayRate)
    {
        if (HoursWorked<=40)
            TotalPay=HoursWorked*PayRate;
        else
            TotalPay=(40*PayRate)+(HoursWorked-40)*PayRate*1.5;
    }
//    cout<<setw(10)<<FirstName<<"   "<<setw(10)<<LastName<<"   "<<setw(10)<<IDNumber<<"    "<<setw(10)<<HoursWorked<<"  "<<setw(10)<<PayRate<<"   "<<endl;
    cout<<setw(10)<<LastName<<"    "<<setw(10)<<IDNumber<<"   "<<setw(10)<<TotalPay<<endl;
}
 
 

Thanks alot.

J

U need to convert those char arrays into integer and then u can use them like u use them now.

Check out function itoa

PS:U are working in c++,arrays of chars are used in c,in c++ u have strings
Savage

[Hypnotik]

So is it possible to type cast the arrays that contains the info I need to multiply?

J

[JosAH]

So is it possible to type cast the arrays that contains the info I need to multiply?

J

Don't do that; simply define your numeric variables as a double or int or whatever
you find suitable; as in:

double HoursWorked;

The >> operator is overloaded for those types and you can read sequences of
input characters as doubles or ints ... no need to convert char arrays yourself.
You're programming in C++, not C, make good use of that language.

kind regards,

Jos

[Hypnotik]

Hey Jos. I'm a bit confused. I have HoursWorked declared as a char array. Do you suggest I create a new "double" variable?? I created HoursWorked1 and I still receive an error for converting char to double.

I guess I'm more than a little confused.

J

[JosAH]

Hey Jos. I'm a bit confused. I have HoursWorked declared as a char array. Do you suggest I create a new "double" variable?? I created HoursWorked1 and I still receive an error for converting char to double.

I guess I'm more than a little confused.

J

Don't do that; simply define HoursWorked (and the other numeric variables) as
doubles, ints, etc. Don't use char arrays for them. That's all you need to do to
get your numbers read from the istream. Don't even define additional variables;
they have no use.

kind regards,

Jos

[Hypnotik]

That is actually how I began the program, however I loose my column headings when I do that.

[JosAH]

That is actually how I began the program, however I loose my column headings when I do that.

Your column headings are a 'special' row (the first one I presume); read that row
using those char arrays if you want but don't read the actual data rows like that.

kind regards,

Jos

[Hypnotik]

Ok, so I've worked with the code. I took in the file heading, and I've created another input file pointer. Although I am unsure how to point to the beginning of the second row.

 
#include <iostream>
#include <fstream>
#include <iomanip>
using namespace std;
void main()
{
    int HoursWorked=0,TotalPay=0,IDNumber=0,PayRate=0;
    char FirstName[10]={0}, LastName[10]={0};
    ifstream ifp,ifp2;
    ofstream ofp;
    ifp.open("c:\\Documents and Settings\\Jeff Young\\Desktop\\Lab14.in");
    ofp.open("c:\\Pay.out");
    ifp>>FirstName>>LastName>>IDNumber>>HoursWorked>>PayRate;
    while (ifp2>>FirstName>>LastName>>IDNumber>>HoursWorked>>PayRate)
    {
        if (HoursWorked<=40)
            TotalPay=HoursWorked*PayRate;
        else
            TotalPay=(40*PayRate)+(HoursWorked-40)*PayRate*1.5;
    }
//    cout<<setw(10)<<FirstName<<"   "<<setw(10)<<LastName<<"   "<<setw(10)<<"IDNumber"<<"    "<<setw(10)<<"HoursWorked"<<"  "<<setw(10)<<"PayRate"<<"   "<<endl;
    cout<<LastName<<"    "<<setw(10)<<"IDNumber"<<"   "<<setw(10)<<"TotalPay"<<endl<<endl;
}
 
 

Thanks,

J

[JosAH]

Ok, so I've worked with the code. I took in the file heading, and I've created another input file pointer. Although I am unsure how to point to the beginning of the second row.

After you've read the first row, the 'pointer' points to the second row automatically.
You can even read the entire first line and forget all about it if you want. Your
last reply's question wasn't that clear to me so my reply could be completely off.

kind regards,

Jos

[Hypnotik]

I meant I had changed the code to read in the first line, and I was asking how to move to the second line of the file.

My program now outputs the correct headings (LastName, HoursWorked,TotalPay) however it does not output any other information, and I haven't even attempted to manipulate the information.

I've posted the updated code.

I have the ifp while loop commented out, as soon as I uncomment the while loop the output is incorrect.

 
#include <iostream>
#include <fstream>
#include <iomanip>
using namespace std;
void main()
{
    int HoursWorked=0,TotalPay=0,IDNumber=0,PayRate=0;
    char FirstName[10]={0}, LastName[10]={0};
    ifstream ifp,ifp2;
    ofstream ofp;
    ifp.open("c:\\Documents and Settings\\Jeff Young\\Desktop\\Lab14.in");
    ofp.open("c:\\Pay.out");
    ifp>>FirstName>>LastName>>IDNumber>>HoursWorked>>PayRate;
//    while (ifp>>FirstName>>LastName>>IDNumber>>HoursWorked>>PayRate)
//    {
//        if (HoursWorked<=40)
//            TotalPay=HoursWorked*PayRate;
//        else
//            TotalPay=(40*PayRate)+(HoursWorked-40)*PayRate*1.5;
//    }
//    cout<<setw(10)<<FirstName<<"   "<<setw(10)<<LastName<<"   "<<setw(10)<<"IDNumber"<<"    "<<setw(10)<<"HoursWorked"<<"  "<<setw(10)<<"PayRate"<<"   "<<endl;
    cout<<LastName<<"    "<<setw(10)<<"IDNumber"<<"   "<<setw(10)<<"TotalPay"<<endl<<endl;
}
 
 

j

[JosAH]

I meant I had changed the code to read in the first line, and I was asking how to move to the second line of the file.

My program now outputs the correct headings (LastName, HoursWorked,TotalPay) however it does not output any other information, and I haven't even attempted to manipulate the information.

I've posted the updated code.

I have the ifp while loop commented out, as soon as I uncomment the while loop the output is incorrect.

Good; so you do get output don't you? If so that implies there's something wrong
in the body of your while loop. It also implies that everything is nicely converted
to the correct type.

kind regards,

Jos

[Hypnotik]

The exact output I receive from the code I posted is:

LastName IDNumber TotalPay



I don't receive any of the other info which is in the file.

Should my while loop only loop over the information I need to manipulate and eventually output?


BTW: Thanks for all the help/suggestions Jos

[Hypnotik]

Might also help if my output statement is in my loop. That doesn't correct the problem though.

J

[JosAH]

BTW: Thanks for all the help/suggestions Jos

No need to thank me; I didn't do much. Your own idea of putting cout >>
expressions at every location you suspect is a good idea though; I use it all
the time and you are actually able to pinpoint your bug between two locations
that are very near to each other in your code: first everything was fine, second
everything turned out goofy. Between those two points your bug can be found
most of the time. Give it a try.

kind regards,

Jos