How to disable word-wrap in Xcode 4 editor?

David Hancock has it right (Xcode Preferences -> Text Editing -> Indentation and deselect Line wrapping), but just to add on -- even after reading that, I had trouble finding the option. I see now that Editing and Indentation are at the top of the box, but they are only written in clickable text (at least in Xcode 5)... I was expecting more of a conventional tab UI and had skipped right over them the first couple of times I looked.

Just a heads-up for anyone like me who might have accidentally skipped over them too...

Go to Xcode Preferences -> Text Editing -> Indentation and deselect Line wrapping.