- What are the downsides of running certain code on the main thread?
a) It can block the UI.
b) It's against best practices.
c) The main thread can only handle UI code.
- In which circumstances will threading not help your performance?
a) When you have a lengthy layout-related calculation.
b) When you load data from the network.
c) When you load many images from disk.
- Which GCD feature can you use to execute an action when several other actions are done executing?
a) DispatchClub.
b) DispatchGroup.
c) GCD_Group.
- Which of the following is not a benefit of operations?
a) More readable code.
b) Faster code execution.
c) Operations can depend on other operations.
- What's the maximum number of Operations you can run at the same time?
a) There is no hard limit, iOS decides on the fly.
b) 4.
c) 10.
- What is KVO?
a) A way for objects to observe properties of another object.
b) A way to boost the execution speed of threads.
c) A technique that is used to make operations depend on each other.
- How do you start executing operations on an operation queue?
a) By calling start() on the queue.
b) By calling resume() on the queue.
c) By adding operations to it.