Detect changes on NSUserDefaults

Question

I\'m developing an iOS application with latest SDK.

I want to know when a property on NSUserDefaults changes it value.

I have found this, but it

Answer 1

In Xcode help, the overview of UserDefaults class (the swifty name for NSUserDefaults) clearly states:

You can use key-value observing to register observers for specific keys of interest in order to be notified of all updates to a local defaults database. For more details, see Key-Value Observing Programming Guide."

I'll see if I can come up with a quick code-sample, but stack-overflow must be full of KVO samples in swift.