Custom type GetHashCode [duplicate]

Answer 1

I always use exclusive or (Xor) rather than addition, because it doesn't have a tendency to get numbers anywhere (like toward large values). So I would say that

protected override int GetHashCode()
{ return str1.GetHashCode() ^ str2.GetHashCode() ^ str3.GetHashCode(); }

is a better implementation.

You could also try a variation on it, like

protected override int GetHashCode()
{
    unchecked
    {
        return (str1.GetHashCode() * 1369) ^
               (str2.GetHashCode() * 37) ^ str3.GetHashCode();
    }
}

if you want to make sure that switching the values of the strings gives a different result. There's all sorts of methods that can be used for hashing (e.g. universal hashing) so just do a search for hashing methods if that's what you're looking for.