Reading in data using a loop?

Question

Using C++ programing how would I set up a loop that can read in a number, use the number, and then go on to the next number until I reach an end of file indicator?

Here's a little section of the program:

ifstream inData;

inData.open ("numbers.dat");
inData >> Number;
FormatNum();
cout << Number << endl;

Answer 1

Just put the section of code inside a while (!inData.fail()) loop.

Answer 2

while (! inData.eof() )
{
fin >> Number;

if (! inData)
break;

FormatNum();
cout << Number << endl;
}

I'm assuming the FormatNum(); is a function that modifies your input. That little if statement I added is just in case there is a trailing EOL (end of line), which would lead the program to believe there is more data when there really isn't and would lead to a crash. So this if statement checks to see if valid data comes in, if not it exists the loop.

Also the .eof() checks to see if this is the end of file.

Answer 3

Not sure for C++, but for VB, which should be pretty close,

do until filename.eof
what you have
move to next number in file
loop