Why NSInvocation

Question

Why use NSInvocation when you could just call the method? Need to ask this question because I can't understand the need to use this class. What is the advantage of using it over just calling the method like below.

 [myArray addObject:myString];

Additional info: What specific challenges does it resolve/address which can't be addressed by the other method calling options.

Answer 1

One use: You could use it to implement a chain of undo actions - where each different action would be a different method call to undo. You would encapsulate each undo action as a method call wrapped in an NSInvocation object.