Must known iOS concepts for Interview for 5+ years experience

Must known iOS concepts for Interview for 5+ years experience - Part 1

Now a days question may ask in any way so having good knowledge on concept is important. Here are the concepts which they will ask questions.

1. OOPS + Basic related :

Inheritance, Polymorphism, Override, Message passing, Class, Object,

Protocols, Delegate, Categories, Extensions, subClassing, Lazy loading,

Designating Initializers, Method Swizzling, Dot and Arrow Access [],

self without self, Properties, Instance methods, Class methods,

Functions, Methods, Caching in ios, Dequeue, reuse identifier,

coupling concept,

Difference b/w array and linked list,

Can you Access singleton object in @synchronised block

2. Threading:

Dispatch_queues (concurrent,serial,dispatch groups,dispatch semaphores, custom queue,dispatch_after,

dispatch_async,dispatch_sync,dispatch_apply(Submits a block to a dispatch queue for multiple invocations.)

Queue priorities low,high,background,default)

Completion blocks

3. Data base:

Core Data (NSManagedObjectContext, NSPersistantStoreCoordinator, PersistentObjectStore, ManagedObjectModel, SQLite File)

Realm ()

Sqlite3(Zero Configuration,Traditional SQl style)

plist,keychainaccess,NSUserDefaults

4. Swift

Basics:(constants and variables) let and var,

Type Annotation with colon var x : String, declare multiple in a singleline like var x,y,z : Int
Conversion let three = "3" let x = Int(three)
typealias TestInt = Int
Booleans true,false
Tuples : Tuples group multiple values into a single compound value.
let (statusCode, statusMessage) = http404Error
Optionals (Handles the nil values using ? and !)
optional Binding using if let

Error Handling: Do catch (do { stmnt } catch {stmnt }), func throws(throwing functions),

Converting errors to optional values (let try? somefunc()),

Disable error propagation with try!

Assertions and Preconditions

Control Flow for in , continue , switch , repeat, fallthrough, break, return, guard let, #available

Closures(escaping , nonescaping, It is value type)

Enumerations(Associated Values)

SubScripts(shortway to access arrays and dict)

In out params(modify the function params)