C++: Reading CSV file into struct array

Question

I am working on an assignment where I need to read a CSV file of unknown number of lines into an structured array. Only via C++, not C (they don\'t want us to combine both).

Answer 1

Your file pointer is at the end of the file after the while loop to determine the amount of lines. As I see it you've got the clear and reset the file pointer. This link might help you: http://www.cplusplus.com/forum/beginner/11564/

Answer 2

Your first loop reads the stream. It stops when there is nothing else left to read. At that point the stream goes into failure mode (i.e., std::ios_base::failbit gets set) and it will refuse to read anything until it gets somehow restored.

You can restore a file to goid state using file. clear(). That alone won't help, though, as the stream is still at its end. You could seek to the start before reading but I wouldn't do that. Instead, I would read the file in one pass and push_back() each element to a std::vector<items>.

Note that the input you have for each items record probably doesn't quite do what you want it to do: if you really have a CSV file you'll need to read to the separators (e.g. the ,) and ignore the separator after reading the ID. Also, you should always test the state of the stream after reading. Your loop could e.g. look something like this:

for (items i;
      (file >> i.id).ignore(std::numeric_limits<std::streamsize>::max(), ',')
      && std::getline(file, i.name, ',')
      && std::getline(file, i.desc, ',')
      && std::getline(file, i.price, ',')
      && std::getline(file, i.pcs); ) {
    is.push_back(i);
}

What is needed exactly somewhat depends on the exact file format.