An easier way to get the count of either lines, or entries per line would do what SGaist suggested where you read the file in line by line into multiple buffers or the whole file into one giant buffer. Then use QString's split function with either the , or \n as your delimiter. The split function returns a QStringList which contains a count.

But, if I have understood you correctly you want to count all the elements contained in your csv. You could read your file line by line in a QString, and use split with the delimiter to get the actual count of the elements per line.

@int kmean_algorithm::calculateElementsInFile()
{
int numberOfElements = 0;
int fileIterator
QFile file("...\iris.csv");
if(!file.open(QIODevice::ReadOnly))
{
QMessageBox::warning(0, "Error", file.errorString());
}
if(file.isOpen())
{
while(file >> fileIterator)
{
numberOfElements ++;
}
}
file.close();
}@

The code provided is wrong and I realize it, as >> is from fstream (if I loaded the file with standard c++ as follows ifstream file(filename); there would be no problem), as I load the file using QFile it means that file >> fileIterator is impossible w.r.t the following error about types inequality:

bq. error: no match for 'operator>>' (operand types are 'QFile' and 'int')

Q: How can I make >> in my case to work? Any suggestion? Alternatives?

You are not very clear. Are you trying to get data from a file or do bit shifting ?