post  Reading in arrays from file

triz (8)   Link to this post
I know the code is horrible and I'm sorry for that. I'm new to programming. I'm trying to read in a list of numbers like this:

3 3 15
123 5 4 3
124 2 5 5
125 3 5 2

It successfully opens the file, but I can't get it to read in the numbers. I'm trying to avoid multi-dimensional arrays. Any help would be greatly appreciated.


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



using namespace std;

const int  fileNameSize  =  32;


 int  main()
  {

    int lineCount;
	ifstream  ins;
	
	
    char fileName[fileNameSize];

    cout  <<  "Enter filename: ";
    cin   >>  fileName;

    ins.open( fileName );
 
    if  ( ins.fail() )
    {cout  <<  "Error opening the file: "  <<  fileName <<  endl;}
    
	else
    {cout  <<  "Successfully opened file: " << fileName <<  endl;


ins.close();


return 0;


string line;
lineCount = 0;
getline(ins, line);
while (line.length() != 0)
{
	lineCount++;
	getline (ins,line);
}

    }


cin.get();
cin.get(); 
    return  0;
  }
kbw (1514)   Link to this post
Do you want to read all the numbers into a single 1D array? If so:
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#incluide <iostream>
#incluide <vector>

int main()
{
    std::vector<int> a;
    int n;

    std::ifstream is("numbers.txt");
    while (is >> n)
        a.push_back(n);

    return 0;
}
triz (8)   Link to this post
I actually want to read it in one line at a time. I added the code below and it now reads in the whole file, except the last line, but I want to read in one line at a time and break that down into an array with it able to identify separate parts, for example,

line one:
cout << array[0] << endl; with the first number being displayed.

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string line;
lineCount = 0;
getline(ins, line);

while (!ins.eof())
{
	lineCount++;
	cout << line << endl;
	getline (ins,line);
	
	
}
kbw (1514)   Link to this post
Don't test for eof, test the stream state directly.
gcampton (782)   Link to this post
whats wrong with testin eof?

not trying to hijack but I have code in my assignment I just did as so:

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void inputArray()
{
    try
    {
        ifstream input( getInputFileName().c_str() );
        string line;
        int count = 0;

        if ( ! input.is_open() )
        {
            cerr << "Failed opening input";
            exit(1);
        }

        while ( ! input.eof() )
        {
            getline( input, line );
            array[count++] << line;
        }
    }
    catch (...)
    {
        cerr << "Error processing file to array";
        exit(1);
    }
}

Last edited on
Duoas (3504)   Link to this post
Infinite loops.
http://www.cplusplus.com/forum/beginner/3470/#msg14566
http://www.cplusplus.com/forum/general/15936/#msg78881
Hope this helps.

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