Empty Function Not Working?

[TweedleGun]

Hello there, I'm trying to detect when the enter key is pressed to break an input loop as follows:

int main()
{
    string words[100];
    int i = 0;
    bool checkEnter = true;

    do {
        cin >> words[i];
        if ((words[i].empty()) && (i>1)) {
            checkEnter = false;
            break;
        }
        i++;
    } while (checkEnter);
    return 0;
}

But the program doesn't end when I press enter without inputting anything (even after I've inputted a few words already). Anyone know what I'm doing wrong?

[IceThatJaw]

http://www.cplusplus.com/forum/beginner/2624/

[xismn]

Here's a thread from 2008, which I hope is relevant:
http://www.cplusplus.com/forum/beginner/2624/

[IceThatJaw]

I misunderstood the question and then googled the same thread in mere secs.

The under-utilization of google on threads like this makes me sad. It's easily the best way to learn.

[TweedleGun]

Guys I'm not ignorant, I've been trying to solve this for a couple hours, and have searched around heaps. The problem with the topic you linked is that the second poster either uses cin.get() or empty(). I don't want to use cin.get() because I need the user to input an entire word (if he/she hasn't finished typing in words) and store it into a string array. I also don't want to use getline because I want the user to input a single word only. And so I am trying the empty function and using cin yet it's not working.

EDIT: If I am wrong and that topic does show what I'm trying to do (apologies, I didn't understand it since I'm not acquainted with all the things he used) then please explain why my program doesn't work.

[Duthomhas]

You are trying to do something at odds with the way things work.

(1) You want to input a word, bounded by any throwaway whitespace
(2) You want to test whether the user only pressed a specific whitespace character

Your options are to use cin.get() to read a character-by-character and build your word that way, or to use std::getline() and s.empty() and then a std::istringstream to break the line into individual words (which is exactly what the second example does, except with integers instead of words).

Hope this helps.

[long double main]

cin >> anything; will gobble up any leading whitespace, so you won't be able to detect just an Enter key press with it.
So, we're going to have to do things slightly differently:

#include <iostream>
#include <string>

int main()
{
    std::cout << "Enter something (or nothing): ";
    std::string input;
    if (std::cin.peek() == '\n') // Peek at the next character (stops for input if there is none)
        std::cout << "You entered nothing. Why'd you do that?!";
    else
    {
        // Now actually get the input
        std::cin >> input;
        std::cout << "You entered: " << input;
    }
}

If you put this in a loop, you'll also want to #include <limits> and put a std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n'); after the std::cin >> input; line; otherwise, it'll leave a newline in the input buffer afterwards and that will get picked up by std::cin.peek() in the next iteration instead of any new input you might have.