NSUserDefaults does not in Preferences?

Question

As everybody know, NSUserDefaults is saved in Library/Preferences.

But....

After I delete com.XXXX.OOO.plist in Library/Preferences/, Xcode still can read Key-Value. Is any other plist at somewhere?

I use Xcode 7.0.1, OS X Yosemite...

Answer 1

I had tried command

defaults delete com.XXXX.OOO.plist

or

rm ~/Library/Preferences/com.XXXX.OOO.plist

But.... it does not work immediately..
It has to kill cfprefsd process to refresh NSUserDefaults

killall cfprefsd