simple cin question

I'm trying to read in a string that I'm throwing into a char buff[100]....

but I need the spaces .... so when I enter "this life"...it only takes "this"...

I tried to use

Code:

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cin.getline(buff, 100)

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but that didn't work

I also tried to use

Code:

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getline(cin, buff)

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with no third parameter for delimiters cause I don't need any...but that just throw errors all over the place so I'm not so sure what I should use and why cin sucks so bad!! Or maybe I just suck and cin is ok.....Any help would be appreciated

Use a string, not a char array.

Code:

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#include <iostream>

int main(int argc, char *argv[])
{
        //char buf[100]; /* Not this. */
        std::string buf;
       
        getline(std::cin,buf);

        ...
       
        return 0;
}

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You could use:

Code:

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getline(cin, VARIABLE, '\n');

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Quote:

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Use a string, not a char array.

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If he wants to use a char array, he can use a char array. (Of course it's easier to use a C++ string, but maybe he wants to experiment with C-strings?)

Of course, he can use a char array, but getline() only works on strings I believe. Besides, this is a much easier way to read off an entire line. In C, reading an entire line can be more of a mess with memory management and pointers, at least for a beginner.

There are two version of getline, one for strings, one for char arrays. Obviously I'd suggest using the string version only because I'd suggest using strings rather than char arrays.

If either getline isn't working, post the full code. One common issue is if you use cin>> before using getline. This leaves a newline in the stream and getline reads that newline and stops. The solution is to add cin.ignore() after the cin >> call to ignore that newline.

It seems to me that:

Code:

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cin.getline(buff, 100);

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should work. How does it not work?

Can we ban all posts that only describe problems as code that "doesn't work" or any variation of it? :) lol....

What laserlight just said, should work. Out of habit, if working with the operator I generally unset skipws when working with chars.

in.unsetf(ios::skipws); // don't skip whitespaces

hmmmmmmmmmmmm neither one of those worked....the

Code:

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getline(std::cin,buf)

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compiled but just skipped over the entire input question

Code:

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getLine(cin, VARIABLE, '\n')

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threw a bunch of errors saying that getLine() only takes 2 arguments but 3 were provided.

agghhhhh

As far as I can tell, getLine() does not exist. C++ identifiers are case sensitive.

Try:

Code:

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#include <iostream>

int main()
{
    char buff[100];
    std::cin.getline(buff, 100);
    std::cout << buff << std::endl;
}

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>> getline(std::cin,buf) compiled but just skipped over the entire input question
There are two common causes to this. One is if you are using Visual C++ 6.0. There is a bug in that compiler's standard library. If you are using that compiler, let us know and we can point you to the bug fix.

The other reason is the one I mentioned above. Are you using cin >> for other data before you call getline?

laserlight your suggestion just skipped over the input again. I'm at a loss.

here's the code I used:

Code:

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cout << "Enter book title: " << endl;
                std::cin.getline(buf, 100);

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with char buf[100]; declaration.....

And I'm using Visual C++ Express 8.0

Post the smallest and simplest compilable program that demonstrates the problem. As Daved pointed out, you could have other nearby (or not so nearby) code that is interfering.

Are you using cin >> for other data before you call getline?

here's my basic stuff...obviously not finished yet...

Code:

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#include "stdafx.h"
#include <iostream>
#include <istream>
#include <string>
#include "Recording.h"
#include "Book.h"
#include "Holding.h"

using namespace std;


int main(void)
{
        //need to declare an array of five pointers to Holding

        char holdingChoice, toLowerChoice;
        char bookTitle[100] , bookAuthor[100], recordingTitle[100], recordingPerformer[100],recordingFormat[100];
        int bookCallNum, recordingCallNum;
        char buf[100];

        cout << "Enter holdings to be stored in list: " << endl;

        cout << "\nEnter B for book or R for recording: " << endl;
        cin >> holdingChoice;

        toLowerChoice = tolower(holdingChoice);
        if(toLowerChoice == 'b')
        {
                cout << "Enter book title: " << endl;
                std::cin.getline(buf, 100);

                cout << "Enter author: " << endl;
                cin >> bookAuthor;

                cout << "Enter call number: " << endl;
                cin >> bookCallNum;
        }
        else if(toLowerChoice = 'r')
        {
                cout << "Enter recording title: " << endl;
                cin >> recordingTitle;

                cout << "Enter performer: " << endl;
                cin >> recordingPerformer;

                cout << "Enter format: " << endl;
                cin >> recordingFormat;

                cout << "Enter call number: " << endl;
                cin >> recordingCallNum;
        }

       


        return 0;
}

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You ran into the exact problem that Daved described.

Change:

Code:

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cout << "\nEnter B for book or R for recording: " << endl;
cin >> holdingChoice;

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to:

Code:

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cout << "\nEnter B for book or R for recording: " << endl;
cin >> holdingChoice;
cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');

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You should #include <limits> too. The reason for this is that your cin >> holdingChoice leaves a newline in the buffer, and you need to ignore this otherwise your cin.getline() call will read until this newline, instead of the next.

The problem is that your first call to cin leaves a newline on the buffer. getline reads this and returns. A call to ignore should do the trick

Code:

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std::ignore('\n', 10);
std::cin.getline(buff, 100);

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Quote:

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Originally Posted by Daved

Are you using cin >> for other data before you call getline?

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and yes I'm using cin >> on a char input above ... see the code....thanks.

Quote:

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Originally Posted by UMR_Student

The problem is that your first call to cin leaves a newline on the buffer. getline reads this and returns. A call to ignore should do the trick

Code:

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std::ignore('\n', 10);
std::cin.getline(buff, 100);

---

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sorry so many "noob" dumb questions but it says that ignore is not a member of std....

You're right, it's not. That's a mistype, sorry. Use laserlight's solution anyway, it's better.

Nevermind I just need to do std::cin.ignore('\n', 10);

Is that need after I use cin.getline() as well or just if I happen to use cin. Meaning will using cin.getline leave a '\n' character in the buffer??

UMR_Student made another typographical error, I am afraid. The arguments are swapped, in that the number of characters to ignore is the first argument, not the second.

Quote:

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Is that need after I use cin.getline() as well or just if I happen to use cin. Meaning will using cin.getline leave a '\n' character in the buffer?

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All forms of getline() for input streams will remove the newline sequence from the buffer, hence there is no need to use ignore() with them.

Yeah, that was all kinds of wrong. Haste makes waste, as they say. Thanks for the corrections anyway.

Now that you've fixed your problem with ignore(), go back to using string instead of character arrays.

Quote:

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Originally Posted by Daved

Now that you've fixed your problem with ignore(), go back to using string instead of character arrays.

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haha....i agree except this is the parameters the professor set...so I'm screwed....he also appauls at int main(...)...he prefers us to use void main(void)...go figure...I can't wait to get out in the real world that way I can be thoroughly frustrated but at least I'll be doing it correctly....

Quote:

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Originally Posted by verbity

haha....i agree except this is the parameters the professor set...so I'm screwed....he also appauls at int main(...)...he prefers us to use void main(void)...go figure...I can't wait to get out in the real world that way I can be thoroughly frustrated but at least I'll be doing it correctly....

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If he is appauled at the standard and fights against it, why is he teaching C++?

Sorry, rhetorical question I guess.