std::getline weird problem

[Vladimir Lushnikov]

Hi,

I have just started learning C++ and have been trying to do simple
string manipulation. However, when calling this function:

int helloString()
{
string name;

cout << "Please enter your name:\n";
getline(cin, name);
cout << "Length of string: " << name.length() << "\n";

return 0;
}

The compiled program gives absolutely no control for the user to type
the string in, so the length of it is always zero. helloString() is
called out of main() in a switch() statement [if that knowledge helps].

So does anyone know what the problem is, and why it won't let me type
anything in befere continuing as normal?

Thanks,
Vladimir Lushnikov

[Pete Becker]

Vladimir Lushnikov wrote:

The compiled program gives absolutely no control for the user to type
the string in, so the length of it is always zero. helloString() is
called out of main() in a switch() statement [if that knowledge helps].

The way to track down the cause of this sort of problem is to simplify.
Remove the switch and call the function directly; if that does the same
thing, then the problem is in the function; if it works right, the
problem is elsewhere.

--

Pete Becker
Dinkumware, Ltd. (http://www.dinkumware.com)

[Dave]

"Vladimir Lushnikov" <vl************ ****@gmail.com> wrote in message
news:11******** **************@ g44g2000cwa.goo glegroups.com.. .

Hi,

I have just started learning C++ and have been trying to do simple
string manipulation. However, when calling this function:

int helloString()
{
string name;

cout << "Please enter your name:\n";
getline(cin, name);
cout << "Length of string: " << name.length() << "\n";

return 0;
}

The compiled program gives absolutely no control for the user to type
the string in, so the length of it is always zero. helloString() is
called out of main() in a switch() statement [if that knowledge helps].

So does anyone know what the problem is, and why it won't let me type
anything in befere continuing as normal?

Thanks,
Vladimir Lushnikov

If by chance you're using Visual C++ 6.0, there is a known problem with
std::getline() in that compiler's Standard Library implementation. A fix is
available (ask for more info if you're on that platform). If you're on any
other platform, please disregard this reply.

[Vyacheslav Kononenko]

Vladimir Lushnikov wrote:

The compiled program gives absolutely no control for the user to type
the string in, so the length of it is always zero. helloString() is
called out of main() in a switch() statement [if that knowledge helps].

So does anyone know what the problem is, and why it won't let me type
anything in befere continuing as normal?

Thanks,
Vladimir Lushnikov

I suspect you do something like cin >> choice; switch( choice ) in your
code before this. If so read this
http://groups-beta.google.com/group/...4f10305a600bcc

Regards,
Vyacheslav

[Vladimir Lushnikov]

Yes, I am using both Visual C++ and cin >> choice;

I also tried this in Cygwin-GCC and it is the same problem. Adding

cin.ignore(nume ric_limits<stre amsize>::max(), '\n');

did solve the problem.

Thanks

[Dave]

"Vladimir Lushnikov" <vl************ ****@gmail.com> wrote in message
news:11******** **************@ g49g2000cwa.goo glegroups.com.. .

Yes, I am using both Visual C++ and cin >> choice;

I also tried this in Cygwin-GCC and it is the same problem. Adding

cin.ignore(nume ric_limits<stre amsize>::max(), '\n');

did solve the problem.

Thanks

Have a look at:

http://www.dinkumware.com/vc_fixes.html

Look at the section entitled "Fix to <string>".

[Pete Becker]

Dave wrote:

"Vladimir Lushnikov" <vl************ ****@gmail.com> wrote in message
news:11******** **************@ g49g2000cwa.goo glegroups.com.. .

Yes, I am using both Visual C++ and cin >> choice;

I also tried this in Cygwin-GCC and it is the same problem. Adding

cin.ignore(nu meric_limits<st reamsize>::max( ), '\n');

did solve the problem.

Thanks

Have a look at:

http://www.dinkumware.com/vc_fixes.html

Look at the section entitled "Fix to <string>".

That patch is always a good idea, but it's not related to the original
question.

--

Pete Becker
Dinkumware, Ltd. (http://www.dinkumware.com)

[Vladimir Lushnikov]

I'm using the Visual Studio.NET 2005 Beta 2 :)

Thanks for your help everyone.