unfamiliar with using files c++

[jimJohnson]

I am working on an assignment and was wanting to know if one of u guys could let me know if I have 1. correct before I go to 2.

Here are the instructions...

1. read in the data then displayed the data.
2 Add the following
a. add a data structure to hold the data
b. read in the data from the input file
c. store the data in the data structure
d. write the data to a output file!

here is my code

#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;

//Start main
int main()
{

	string filename = "exam.txt"; // Create Var to hold file name
	char inputline[80]; // Buffer to hold line just read
	ifstream inFile; // Input file object


	// Open the input file.
	inFile.open("exam.txt");

	// Test for errors.
	if (!inFile)
	{
		cout << "Error opening " << filename << endl;
		exit(EXIT_FAILURE);
	}

	// Read through file & list names
	// Read and process the input file.

	while (!inFile.eof())
	{
		// Read the string from inFile.
		inFile.getline(inputline, 80, '\n');

		// Display the line.
		cout << inputline << endl;
	}

return 0;
}

[Dave Sinkula]

Avoid Loop Control Using eof()

[jimJohnson]

I apologize for coming off as a complete idiot when i say this but I dont know much about c++ and not really sure what u mean

[Murtan]

It was a link to another thread that explains why not to use eof() in your while loop condition. Click the link, read the thread and implement the change.

[jimJohnson]

here is my problem...i am not able to make changes to the following code and i can only add from it and it seems like there is alot of missing information but could be wrong..

#include
#include
#include

using namespace std;


int main()
{

string filename = "names.txt"; // Create Var to hold file name
char inputline[80]; // Buffer to hold line just read
ifstream inFile; // Input file object


// Open the input file.
inFile.open("name.txt");

// Test for errors.
if (!inFile)
{
cout << "Error opening "
<< filename << endl;
exit(EXIT_FAILURE);
}

// Read through file & list names


// Read and process the input file.

while (!inFile.eof())
{

// Read the string from inFile.
inFile.getline(inputline, 80, '\n');


// Display the line.
cout << inputline << endl;




}


return 0;

}

[necrolin]

First thing I noticed was:

string filename = "names.txt"; // Create Var to hold file name
   inFile.open("name.txt");

Why are you creating a variable and then not using it?

About your include "cmath", so far you don't really need it.

Part 1 works fine. I was thinking that you could simplify your code in the long run by reading everything into your data structure and then from there you can use a single loop to to display the contents to the screen and output it to a file. Otherwise you'll have to read the file again so that you can put the data into the data structure, which seems like unnecessary work if you ask me.

[jonsca]

inFile.open(filename.c_str()); will open up the file using the filename (that c_str() method provides the C string representation)