Most Asked Questions For IOS Developer In Interview

The future of iOS app developers looks bright because of the rise in the number of iOS users. iOS and Apple’s loyal customer base have led to innovative devices such as Apple Watch and Apple TV.

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?

A temporary container for multiple values is called a tuple. It is a list comma-separated type and is enclosed in parentheses.

What is the difference between retaining and copy?

A reference to the instance is stored, and the same is shared with anyone who retained it. At the same time, copy means that the object will be cloned with duplicated value, but it cannot be shared with anyone else.

What do you understand by category?

A category is a way to add additional methods to a class without extending it. It is used to add a collection of related methods and additional methods to built-in classes in the Cocoa Frameworks.

What do you understand by dynamic dispatch?

The process of selecting which implementation of a polymorphic operation to call at run time is called Dynamic dispatch. It is used when we need to invoke our methods like the object method.

What is responder chain?

A responder chain is a hierarchy of objects that have the chance of responding to the received events.


As an iOS developer, you should stay updated with the changes in the iOS community. Follow Apple developer news, read blogs, listen to podcasts and be keen to learn new things.