Getline keeps on getting newline character. How can I avoid this?

Question

Basically I first takes an integer as input and then test case follows. My each test case is an string. I am suppose to print the string back if the starting patten of strin

Answer 1

I am writing this answer with the hopes that it may help someone else out there that wants a very simple solution to this problem.

In my case the problem was due to some files having different line endings such as '\r' vs. '\n'. Everything worked fine in windows but then it failed in Linux.

The answer was actually simple. I created a function removeNewLineChar after each line was read in. That way the char was removed. The removeNewLineChar takes in the line that was read in and copies it over character by character into a new string but it avoids copying either of the newline characters.

Here is a full explanation of how that works.

C++ getline reads in the newline character and how to avoid it

Answer 2

So, your real problem isn't that getline eats newlines, but that your second getline(cin, ne) is eating a line...

And that is because you mistakenly think that you need two getline operations to read one line - or something like that. Mixing "linebased" and "itembased" input does have confusing ways to deal with newlines, so you do need something to "skip" the newline left behind frin cin >> N;, but once you have got rid of that, you only need ONE getline to read up and including the newline at the end of a line.

Answer 3

Your cin >>N stops at the first non-numeric character, which is the newline. This you have a getline to read past it, that's good.

Each additional getline after that reads the entire line, including the newline at the end. By putting in a second getline you're skipping half your input.

Answer 4

ignore() function does the trick. By default, it discards all the input suquences till new line character.

Other dilimiters and char limit can be specified as well.

http://www.cplusplus.com/reference/istream/istream/ignore/

In your case it goes like this.

    cin >> N;
    cin.ignore();

Answer 5

cin.ignore() worked for me.

void House::provideRoomName()
{
    int noOfRooms;

    cout<<"Enter the number of Rooms::";
    cin>>noOfRooms;
    cout<<endl;

    cout<<"Enter name of the Rooms::"<<endl;
    cin.ignore();
    for(int i=1; i<=noOfRooms; i++)
    {
        std::string l_roomName;
        cout<<"Room"<<"["<<i<<"] Name::";
        std::getline(std::cin, l_roomName);
    }
}

Answer 6

you just need to accept the fact that getline will give you '\n' at the end. One solution is remove '\n' after getting it. Another solution is do not write the additional 'endl'. for example, for your problem, you can use this code

int N;
cin >> N;
string line;
getline(cin, line); // skip the first new line after N.
for (int i = 0; i < N; i++) {
  string line;
  getline(cin, line);
  string first4 = line.substr(0, 4);
  // convert to upper case.
  std::transform(first4.begin(), first4.end(), first4.begin(), std::ptr_fun<int, int>(std::toupper)); // see http://en.cppreference.com/w/cpp/algorithm/transform
  if (first4 == "HI A") {
    cout << line;  // do not include "<< endl"
  }
}