Where is a Mac Application's NSUserDefaults Data Stored?

Question

I am using NSUserDefaults to store some data in my application.

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
[prefs setObject:@\"dummy stri         


        

Answer 1

One more possible location for these data comes into play when trying things out in a Playground. I was experimenting with UserDefaults in a Playground, using XCode 8.3 and Swift 3, and wanted to see the resulting plist file. After some detective work (UserDefaults files have the bundle identifier in the filename and calling Bundle.main.bundleIdentifier in a Playground gives the XCode identifier) I found to my great surprise that the UserDefaults data was added to:

~/Library/Preferences/com.apple.dt.Xcode

In other words, keys and values are added to the XCode preferences file! I double-checked by coming up with very unlikely strings for the keys and they were indeed added there. I did not have the courage to try using some keys that were already in use by XCode but caution seems good here.