cin.get not taking input?

[jleach]

Hi,

I've noticed the following behavior using cin.get() and am not sure why... I'm hoping someone may be able to enlighten me.

#include <iostream>
#include <string>
using namespace std;

char cLastInput[50];

int main()
{

   string sFirstName;
   string sLastName;

   cout << "First Name: ";
   cin.get(cLastInput, 50);
   sFirstName = string(cLastInput);

   cout << "\nLast Name: ";
   cin.get(cLastInput, 50);
   sLastName = string(cLastInput);

   cout << "\n\n" << sFirstName << " " << sLastName;

   return 0;
}

First Name: Jack

Last Name: Jack
Process returned 0 (0x0)   execution time : 2.200 s
Press any key to continue.

The program takes the first name input, but does not prompt me for the last name input, and seems to retain the value of cLastInput for the second cin.get() call.

My intent was to use a single variable to hold temp input that could be converted to a string and applied to variables, though it appears that subsequent cin.get() calls using the same variable as the last call without prompting in the console for a replacement.

Could somebody possibly explain why cin.get() does this?


For further background, I've come to use cin.get() as it seems to be the most convenient way to return a string from the console that does not break on a space. So far, through minor excersizes to familiarize myself with some basic ins and outs of c++, this is the best I've gotten to yet. Should I instead be looking at stringstreams, instead of strings and char arrays? I will look into them, as I haven't yet, but I'd still be curious to know the reason for this cin.get() behavior.

Many thanks in advance,
Jack

[Duthomhas]

It is behaving as expected. The first call to cin.get() gets everything the user typed except the newline. It is still sitting in the stream. If what you want is string input, use the string functions.

#include <iostream>
#include <string>
using namespace std;

int main()
{

   string sFirstName;
   string sLastName;

   cout << "First Name: ";
   getline( cin, sFirstName );

   cout << "\nLast Name: ";
   getline( cin, sLastName );

   cout << "\n\n" << sFirstName << " " << sLastName;

   return 0;
}

If you must use the c-string input functions, use the istream::getline() function

#include <iostream>
#include <string>
using namespace std;

char cLastInput[50];

int main()
{

   string sFirstName;
   string sLastName;

   cout << "First Name: ";
   cin.getline( cLastInput, sizeof(cLastInput) );
   sFirstName = cLastInput;

   cout << "\nLast Name: ";
   cin.getline( cLastInput, sizeof(cLastInput) );
   sLastName = cLastInput;

   cout << "\n\n" << sFirstName << " " << sLastName;

   return 0;
}

On a more personal note, Hungarian notation needs to die a horrible death.

Hope this helps.

[jleach]

It is behaving as expected. The first call to cin.get() gets everything the user typed except the newline. It is still sitting in the stream.

Duh... I read about this in the sticky "console won't stay open thread". Sorry...

If what you want is string input, use the string functions. [...] If you must use the c-string input functions, use the istream::getline() function

Thanks, I will check these out. I started first with plain old "cin" and a char variable, and then found how to use cin.get() and convert it to string. I'll take a look at string input functions.

Hungarian notation needs to die a horrible death.

Yea, I know... I still haven't found a decent naming convention to use for c++ yet. The use of Hungarian is leftover from my VB work (not so many problems with it there, but we leave it off for working with classes).

Thanks Duoas