Help with cin.fail()

[anonymous]

Hi,

I need some help with cin.fail()

I'm making a program that accepts an integer and asks for in to be put in again if it is not an integer. My code:

 
     do
     {
        valid = true;
 
         cout << "Enter an integer: ";
        cin >> number;
 
        if(cin.fail())
        {
            cout << "Error! Please enter integer value! " << endl;
            cin.clear();
            cin.ignore(50, '\n');
            valid = false;
        }
    }
    while(!valid);
 
 

works partially.

It only works if the first 'charater' (?) is a character,
i.e. number = i123

but if number = 123i321

then is takes number ase 123, which is not what i want. I want it to ask for a new input.

I hope its possible, i'm assuming it'll be a simple fix, thanks for any help given.

[Banfa]

This is a common problem with these functions.

You will have to read the user input as a string (use getline or something) and then validate and convert the function to binary yourself.

This is not as hard as it sounds as the c function

strtoul

performs pretty much everything you require