terminate called after throwing an instance of 'std::out_of_range' error

Question

I'm a newbie. For a school project, I need a typewriter, and I came down to this idea that seems good to me. But when I launch it, it says this error:

terminate called after throwing an instance of 'std::out_of_range' error

I don't know why. I think the idea is good, because when I try without the variable t, so just putting numbers in testo.erase(), it works, but I need to create a loop.

void typewriter(string testo, int tempo)
{
    int i = testo.length();
    int t = 0;
    while (t<=i)
    {
        system ("CLS");
        t=t+1;
        testo.erase(t);
        cout<<testo;
        Sleep(tempo);
    }
}

Answer 1

This is because you are erasing the characters, which shortens the string. I think that changing testo.erase(t) to test.erase(0) should fix it.

Also, as πάντα ῥεῖ said, it should be t < i instead of t <= i. But, this is an unnecessary change, as with the erasing of characters.

Answer 2

Thanks, I resolved it by reassigning the string testo every time I join in the while loop:

void typewriter(string testo, int tempo)
{
    int i = testo.length();
    int t = 0;
    string testo1 = testo;
    while (t<i)
    {
        testo1 = testo;
        system ("CLS");
        t=t+1;
        testo1.erase(t);
        cout<<testo1;
        Sleep(tempo);
    }
}