50 iOS Interview Questions And Answers

Durul Dalkanat
13 min readDec 27, 2016

Updated on Nov, 2023

1- How could you set up Live Rendering?
The attribute @IBDesignable lets Interface Builder perform live updates on a particular view. IBDesignable requires Init frame to be defined as well in UIView class.

2- What is the difference between Synchronous & Asynchronous task?
Synchronous: waits until the task has been completed Asynchronous: completes a task in the background and can notify you when complete

3- Explain Compilation Conditions

Compilation Conditions to use if DEBUG … endif structure to include or disable given block of code ve separate targets.

4- What is made up of an NSError object?
There are three parts of the NSError object a domain, an error code, and a user info dictionary. The domain is a string that identifies what categories of errors this error is coming from.

5- What is Enum or Enumerations?

According to Apple’s Swift documentation:

Managing state, the bits of data that keep track of how the app is being used at the moment, is an important part of a developing your app. Because…