Question

What I’m attempting to accomplish, is to open an external .dat file using “ifstream” then read each double into a vector array.

What I have:

//Setup I/O
ifstream fileIn;
ofstream fileOut;

//Define vector for file data
vector<double> fileData;

fileIn.open("/FilePath.../checkIn.dat");
//If opening failed, display this text.
if (fileIn.fail( ))
{
    cout << "    Input file opening failed.\n";
    //stop program
    exit(1);
}

The file I’m reading from:

2000 1 1225.72 1 463.81 3 200 1 632 2 1500 1 300 2 1800

I’ve been looking all around the internet, can’t find something useful.
I’m looking for a function similar to “hasNextDouble” in Java.

Answer 1

It sounds to me like you’re trying to imitate Java too closely (i.e., make things much more complex than necessary).

// Open the file
std::ifstream file_in("/FilePath.../checkIn.dat");

// Create the vector, initialized from the numbers in the file:
std::vector<double> fileData((std::istream_iterator<double>(file_in)),
                              std::istream_iterator<double>());

…and you’re done.