[Resolved (Sort of...)] cin.ignore() / cin.get()

[McCain]

Why do I have to hit Return an extra time to exit this program?

//char.cpp

#include <iostream>
using namespace std;

char control();

void main(void)
{
	char ans; 

	ans = control();
	cout << ans << endl;
	cout << cin.get() << endl;
}

char control() 
{
	char c;
	cout << "Y or N: ";
	cin.get(c);
	while (c!= 'Y' && c!= 'N' && c!='y' && c!='n')
		{
		cout << "Y or N: "; 
		cin.get(c);
		cin.ignore(10, '\n');
		}
	cin.ignore(10,'\n');
	return (c);
}

It seems to me that the program stops at cin.get() if there's nothing in the input buffer. Why does it do this?

[The Hobo]

Try this:

//char.cpp

#include <iostream>
using namespace std;

char control();

void main(void)
{
	char ans; 

	ans = control();
	cout << ans << endl;
	cout << cin.get() << endl;
}

char control() 
{
	char c;
	cout << "Y or N: ";
	cin.get(c);
	while (c!= 'Y' && c!= 'N' && c!='y' && c!='n')
		{
		cout << "Y or N: "; 
		cin.ignore();
		cin.get(c);
		}
	return (c);
}

Edit: Nevermind, I still see problems.

[McCain]

What exactly does cin.ignore() do? I know that cin.ignore(10, '\n') deletes 10 characters from the input buffer or untill it finds a \n

[The Hobo]

Originally posted by McCain
What exactly does cin.ignore() do? I know that cin.ignore(10, '\n') deletes 10 characters from the input buffer or untill it finds a \n

cin.ignore() will just clear out the first character in the buffer. I realize now that if someone enters something more than one character, the buffer is going to be larger than that and mess up your program.

This is how I'd do it:

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

string control();

void main(void) {
    string ans; 

    ans = control();
    cout << ans << endl;
}

string control() {
    string c;

    cout << "Y or N: ";
    getline(cin, c);

    while (c != "Y" && c != "N" && c != "y" && c != "n") {
        cout << "Y or N: ";
        //cin.ignore(); //if you're using MSVC++, you may need this line...
        getline(cin, c);
    }

    return (c);
}

[McCain]

I know I can use getline, I can also use cin >> but the exersice was to use cin.ignore with cin.get (I'm doing the exercises in a book I've got...)
Thanks anyway for taking the time to help me