I don't get what you mean? The case doesn't change, for objects like QApplication, the case is set in stone. You can't change it, you HAVE to use that casing. Therefore all applications use the same word EXACTLY, including the same case.

Secondly, QtCreator supports code completion. So if you type qapp, it automatically suggests QApplication, and if you type qhb, it will suggest QHBoxLayout, etc. You don't need to remember the case of every letter, although most times its quite obvious.