IOS developer in interview

What is meant by enumerations or enum?

A class type containing a group of related items under the same umbrella, but it is impossible to create an instance of it. 

What do you understand by memento pattern?

A design pattern in which you can save stuff somewhere. This externalized state can be later restored without violating encapsulation and maintaining the privacy of data.

What is the lazy property in swift?

When the property is called for the first time, an initial value of the lazy stored properties is calculated.

What is the difference between ‘bundle ID and ‘app ID’?

The bundle ID is specified in Xcode, and it defines each App. A single project can have multiple targets and can output multiple apps.

From where should UIKit classes be used?

UIKit classes should be used from the application’s main thread only.

When an app is launched, what are its state transitions?

Before launch, an app is not said to be running. After a brief transition through the inactive state, it moves to the background or the active state when it is launched.

What do you understand by iBeacons?

iBeacon is the technology standard by Apple that allows mobile apps to listen from signs from beacons and react accordingly. This technology allows Mobile Apps to understand their position and deliver hyper-contextual content to users based on their location.

What is a tuple in swift?