Weird thing happens whenever I type a letter

[slender parrot]

Hello, I made that my code sends a message whenever it isn't any of options, it works with numbers but whenever it is letter is just goes crazy. Could anyone help me solve this problem? I am pretty beginner with c++ and this error shouldn't be a big deal to spot out I think...

[round yarrow]

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[fast girder]

you are not updating odpowiedz inside the loop of the else block

[slender parrot]

so how should it look like then?

or what should I add

[soft plover]

so what is happening is that when
std::cin >> float fails, it doesn't read anything then sets some flags in std::cin that says "hey there is an error".
If there is an error flag, std::cin will not read any new data until the error is cleared

So as a result, it will just constantly loop the same input and not doing anything

[slender parrot]

uh it sounds complicated

[soft plover]

you can do cin.clear() to clear any errors, then cin.ignore to ignore the character until a new line. here is an example

#include <iostream>
#include <limits>
#include <sstream>
 
constexpr auto max_size = std::numeric_limits<std::streamsize>::max();
 
int main()
{
    std::istringstream input("1\n"
                             "some non-numeric input\n"
                             "2\n");
    for (;;)
    {
        int n;
        input >> n;
 
        if (input.eof() || input.bad())
            break;
        else if (input.fail())
        {
            input.clear(); // unset failbit
            input.ignore(max_size, '\n'); // skip bad input
        }
        else
            std::cout << n << '\n';
    }
}

[slender parrot]

is there any simplier way...?

[soft plover]

Don't input bad inputs :)

[slender parrot]

I wish!

so how can I use it in my code

so it doesn't break

[soft plover]

Joking aside, there is an option to have cin raise an exception on bad inputs. That is an alternative, though I'm not a fan

[slender parrot]

and what is that option?

because if I will use complicated stuff as beginner my teacher will suspect some stuff

[soft plover]

float wartosc_a()
{
    float a;
    cin >> a;
    while (!cin)
    {
        cin.clear();
        cin.ignore((unsigned)-1, '\n');
        cout << "a nie moze byc mniejsze lub rowne 0, podaj nowa wartosc" << endl;
        cin >> a;
    }
    return a;
}

So this is the non exception version

Here is the exception example

#include <fstream>
#include <iostream>
 
int main() 
{
    int ivalue;
    try {
        std::cin.exceptions(std::ifstream::failbit); // may throw
        std::cin >> ivalue; // may throw
    } catch (const std::ios_base::failure& fail) {
        // handle exception here
        std::cout << fail.what() << '\n';
    }
}

[slender parrot]

omg it works

thank you very much! ❤️

!solved