Why is there a blank line?

Question

I have the following C++ program:

ofstream output("scores.txt");
output<<"John"<<" "<<"T"<<" "<<"Smith"<<" "<<90<<endl;
output<<"Eric"<<" "<<"K"<<" "<<"Jones"<<" "<<103<<endl;
output.close();

ifstream input;
input.open("scores.txt");
string line;
while (!input.eof()) {
    getline(input, line);
    cout<<line<<endl;
}
input.close();

cout<<"Done";

The output is:

John T Smith 90
Eric K Jones 103

Done

Why is there a blank line between Eric K Jones 103 and Done?

Is there an empty line at the end of your `scores.txt` file? — hlt, Dec 08 '15 at 18:53
@hlt No. The funny thing is, if I remove the endl, the output is John T Smith 90Eric K Jones 103Done (all on one line). So that can't be the problem. — Siddhartha, Dec 08 '15 at 18:55
@SergioS But I want Eric's data to be printed on a new line. — Siddhartha, Dec 08 '15 at 18:59
@Thomas Eric's data will be printed on a new line already because of the '< — Sergio S, Dec 08 '15 at 19:02

score 0 · Answer 1 · answered Dec 08 '15 at 18:58

Structure your loop like this:

while (getline(input, line)) {
    cout<<line<<endl;
}

Your duplicate line is because the way your read loop is structured, once you read the last line the eof bit is not set yet because readline succeeded. Therefore, you iterate one more time, doing a readline that does set the eof bit, then you do cout<<line<<endl and that last endl is your extra blank line.

Why is there a blank line?

1 Answers1