Question

How can I check if my input is a particular kind of string. So no numeric, no “/”,…

Answer 1

Well, to check that an input is actually an object of type System.String, you can simply do:

bool IsString(object value)
{
    return value is string;
}

To check that a string contains only letters, you could do something like this:

bool IsAllAlphabetic(string value)
{
    foreach (char c in value)
    {
        if (!char.IsLetter(c))
            return false;
    }

    return true;
}

If you wanted to combine these, you could do so:

bool IsAlphabeticString(object value)
{
    string str = value as string;
    return str != null && IsAllAlphabetic(str);
}