fstream getline

[devc1]

I am having trouble reading from a file using fstream as taught by my professor. Reading from a txt of numbers I try to use:

int x[5];
fstream f;
	f.open("data.txt",ios::in);
	for(int i=0;i<=5;i++)
	{
		while(!f.eof())
		{
			f.getline(x[i],19,'/');
		}
	}
	f.close();

Where '/' is delimiter.
I don't understand any form of getline it's trying to make me retype and this site doesn't help me understand either. How would I read properly from a file using fstream?

[Chervil]

Could you show a sample of the contents of the file data.txt please.

[devc1]

44
33
19
9
70
11


I was just using a delimiter as another example of what our professor lectured, but I can't seem to get it compiled either.

[Chervil]

Ok, here's one way:

#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    int x[5];
    
    ifstream f("data.txt");
    // read the numbers from the file
    int ix = 0;
    while (ix <5 && f >> x[ix])
        ix++;
         
    // show the contents of the array
    for (int i=0; i<ix; i++)
        cout << x[i] << endl;
        
    return 0;
}

The while condition may need some explanation. It is checking two separate conditions, first that the array is not full, then that reading of an integer has been successful.

[devc1]

Using ifstream f>>x[i] to get numbers I get incorrect readings

[s]11 -858993460 -858993460 -858993460 -858993460
-858993460
[/s]

Nevermind the method I used to print cause this, thanks, but how would I use getline appropriately? And which is more sufficient ifstream or fstream?

[Chervil]

Here's an example using getline with a delimiter
input:

  545 / 7  / 9 /
11 / 210 /  32 /  17

#include <iostream>
#include <fstream>
#include <cstdlib>

using namespace std;

int main()
{
    int x[5];
    
    ifstream f("data.txt");
    
    int ix = 0;
    string line;
    while (getline(f,line,'/'))
    {
        x[ix] = atoi(line.c_str());
        
        ix++;
        
        if (ix >= 5)
            break;
    }
         
    for (int i=0; i<ix; i++)
        cout << x[i] << endl;
        
    return 0;
}

Output:

545
7
9
11
210

fstream can be used for either input or output (or both).
ifstream does the same job, but is for input only.