Question

Sorry for this extreme noob question,

I am using a for loop with 5 iterations. Each time it loops I prompt the user to enter a decimal, I use cin >> aDouble. If I type in any number it works fine, but if I type in a string it will loop the five times, then go on.

Here’s my code.

for(int i = 0; i <= ARRSIZE; i++)
{
    cout << "Please enter a decimal value: ";
    cin >> myDouble;

    if (!cin.fail() )
    {
        myVector.push_back(myDouble);
    }
}

Thank you!!

Answer 1

Once a stream failed to read a value it sets std::ios_base::failbit and this bit stays set until it gets cleared. While an error bit is set, the stream doesn’t do anything. That is, if cin.fail() is true you deal with the problem as well: You need to get rid of the “string”:

if (std::cin.fail()) {
    std::cin.clear();
    std::cin.ignore();                                  // ignore one character or ....
    std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n'); // rest of line
}