In Objective-C, when are metaclass object and class object created?

Question

In Objective-C, when are the class pairs - metaclass object and class object, created? Is it in the beginning of the app execution or at the point when you first instantiate the first object of a class?

Answer 1

At the point that the class is added to the class hierarchy. This is generally when the app is launched, but could be later if the class is added by a dynamically loaded library or is created programatically.

The class object and metaclass have to exist at the time that +load is called (which is the above).