Tell about block and GCD
Answer / babu
Block: Block objects are a C-level syntactic and runtime feature. Blocks are particularly useful as a callback because the block carries both the code to be executed on callback (on completion handler block) and the data needed during that execution.
GCD: GCD (Grand Central Dispatch) provides and manages FIFO queues to which your application can submit tasks in the form of block objects. Blocks submitted to dispatch queues are executed on a set of threads completely managed by the system. No guarantee is made as to the thread on which a task executes. GCD allows three kinds of queues:
Main: tasks execute serially on your application’s main thread
Concurrent: tasks are dequeued in FIFO order, but run concurrently and can finish in any order.
Serial: tasks execute one at a time in FIFO order
| Is This Answer Correct ? | 0 Yes | 0 No |
How can you respond to state transitions on your app?
What is mvc design pattern in ios?
What is the concurrency how many ways you know to achieve concurrency?
. When an app is said to be in not running state?
What framework is used to construct application's ios user interface?
What is the difference between NSArray and NSMutableArray in iOS operating system?
How to download xcode for iphone development?
Do you know what are layer objects and what do they represent?
An app is loaded into memory but is not executing any code. In which state will it be in?
What is the use of double question marks (“??”) ?
Why do we override drawrect: method?
What is messaging? How does the runtime handle message passing? What is message forwarding?