quick question about getline

hi, i have a little question about cin.getline and cin.get...

Code:

char seleccion(){
    char opcion[5];
    while(true){
        menu1();
        cin.getline(opcion,5);
        cin.clear();
        if(strcmp(opcion,"new") == 0) return 1;
        else if(strcmp(opcion,"show")==0) return 2;
        else if(strcmp(opcion,"mod")==0) return 3;
        else if(strcmp(opcion,"del")==0) return 4;
        else if(strcmp(opcion,"exit")==0) return 5;

    }
}

the problem is that after the first time the getline function doesn't allow me to enter anything, it just fills the string with a newline

like if i do this

Code:

char something[5];
cin.getline(something,5);
cout << something << endl;
cin.getline(something,5);
cout << something << endl;
cin.getline(something,5);
cout << something << endl;

what i get is

Code:

whatever_i_wrote
newline
newline

can please anyone tell me why this happen and what can i do to solve it?


(sorry if it's hard to understand, english isn't my mother language)

I'm not sure why it's happening, though I suspect it's because there's not enough space in opcion to hold the newline and a terminating nul, so the newline is left in the stream.

In any case, don't use C strings.

Code:

#include <string>
int seleccion(){
    using namespace std;
    string opcion;
    while(true){
        menu1();
        getline(cin, opcion);
        cin.clear();
        if(opcion == "new") return 1;
        else if(opcion == "show") return 2;
        else if(opcion == "mod") return 3;
        else if(opcion == "del") return 4;
        else if(opcion == "exit") return 5;

    }
}

Note that I also changed the return type to int. There's no point in using a char there, and it's confusing.

If you are writing in C++ you really are better to use the 'string' type instead of char array, unless you have a very good reason not to, and personally i would change while(true) to your own named boolean variable.
Also with the string type you can avoid using the old c strcmp() function, and instead use the built in string.compare() or even the == operator which is available for the string class. You can see a very handy reference on the string class and all it can do for you here, y tu inglés esta bien...(taking a guess there!! :-> "opción??")