Here is my IsIsogram

bool FBullCowGame::IsIsogram(FString Word) const
{
    if (Word.length() <= 1) { return true; }
    TMap<char, bool> LetterSeen;
    for (auto Letter : Word)
	{
		Letter = tolower(Letter);
		if (LetterSeen[Letter]) 
		{
			return false;
		}
		else
		{
			LetterSeen[Letter] = true;
		}
	}
	
	return true; // Isoteric cases like /0
}