Wont wait for getline C++

Question

I have a console application that shopuld wait for the user to input a string. It has to be getline, because it could contain spaces. But it doesn't wait for input, it skips it and runs the functions anyway. Here's my code:

int main()
{
    vector<person> people;
    bool flag = true;
    int num_people = 0;
    //char*filename="names.txt";

    people = read_file();

    while(flag)
    {
        int sel = 0;
        string args;
        cout << "1 - Sök del av personnamn" << "\n" 
    << "2 - Sök städer" << "\n" << "3 - Avsluta" << endl;
    cin >> sel;
    if(sel == 1)
    {
                cout << "Mata in delen av personnamnet" << endl;
                getline(cin, args);
                print_result(find_in_names(people, args));
    }
    else if(sel == 2)
    {
                cout << "Mata in staden" << endl;
                getline(cin, args);
                args = lower_letters(args);
                print_result(find_person_from_city(people, args));
        }
    else if(sel==3)
    {
        flag=false;
    }
    else
    {
        cout << "FEL, TRYCK OM!" << endl;
    }
    }
}

Runs without errors, it just skips the getline and doesn't let the user input anything.

looks same as Need help. cin is leaving the return key press and it is being read by getline(). — Richard Chambers, Feb 24 '13 at 20:31

score 5 · Accepted Answer · answered Feb 24 '13 at 21:21

Here is a simple way to use the getline() function :

#include <iostream>
#include <string>

using namespace std;

int main(void)
{
    string name;
    int age;

    cout << "How old are you ?" << endl;
    cin >> age;

    cin.ignore();              // for avoiding trouble with 'name' when we're gonne use getline()

    cout << "What's your name ?" << endl;
    getline(cin, name); 

    system("PAUSE");
}

Don't forget it, if you use cin befor getline(), you have to put the line :

cin.ignore();

So your code should looks like something like that :

int main()
{
    vector<person> people;
    bool flag = true;
    int num_people = 0;
    //char*filename="names.txt";

    people = read_file();

    while(flag)
    {
        int sel = 0;
        string args;
        cout << "1 - Sök del av personnamn" << "\n" << "2 - Sök städer" << "\n" << "3 - Avsluta" << endl;
        cin >> sel;

        cin.ignore()

        if(sel == 1)
        {
            cout << "Mata in delen av personnamnet" << endl;
            getline(cin, args);
            print_result(find_in_names(people, args));
        }
        else if(sel == 2)
        {
            cout << "Mata in staden" << endl;
            getline(cin, args);
            args = lower_letters(args);
            print_result(find_person_from_city(people, args));
        }
        else if(sel==3)
        {
            flag=false;
        }
        else
        {
            cout << "FEL, TRYCK OM!" << endl;
        }
    }
}

Here's some doc http://www.cplusplus.com/reference/istream/istream/ignore/, hope it'll help;

Wont wait for getline C++

1 Answers1