• Home
  • Troubleshoot
  • #Example
    • C
    • C++
    • Python
    • R-Programming
  • DSA
  • Quiz
  • Tutorial Videos
  • Home
  • Troubleshoot
  • #Example
    • C
    • C++
    • Python
    • R-Programming
  • DSA
  • Quiz
  • Tutorial Videos
  • #Deals
  • #News
  • #WiKi
  • #APPS
  • #Events
    • #WWDC
    • #I/O
    • #Ignite
  • #Let’s Talk

MyCodeTips mycodetips-newlogocopy1

  • Home
  • Troubleshoot
  • #Example
    • C
    • C++
    • Python
    • R-Programming
  • DSA
  • Quiz
  • Tutorial Videos
IOSQuestions

iphone Interview Questions part-1

1-How would you create your own custom view?

By Subclassing the UIView class.

2-Whats fast enumeration?

Fast enumeration is a language feature that allows you to enumerate over the contents of a collection. (Your code will also run faster because the internal implementation reduces
message send overhead and increases pipelining potential.)

3-Whats a struct?

A struct is a special C data type that encapsulates other pieces of data into a single cohesive unit. Like an object, but built into C.

4-What are mutable and immutable types in Objective C?


Mutable means you can change its contents later but when you mark any object immutable, it means once they are initialized, their values cannot be changed. For example, NSArray, NSString values cannot be changed after initialized.

5-Explain retain counts.

Retain counts are the way in which memory is managed in Objective-C. When you create an object, it has a retain count of 1. When you send an object a retain message, its retain count is incremented by 1. When you send an object a release message, its retain count is decremented by 1. When you send an object a autorelease message, its retain count is decremented by 1 at some stage in the future. If an objectʼs retain count is reduced to 0, it is deallocated.

6-Whats the difference between frame and bounds?

The frame of a view is the rectangle, expressed as a location (x,y) and size (width,height) relative to the superview it is contained within. The bounds of a view is the rectangle, expressed as a location (x,y) and size (width,height) relative to its own coordinate system (0,0).

7-Is a delegate retained?

No, the delegate is never retained! Ever!

8-Outline the class hierarchy for a UIButton until NSObject.

UIButton inherits from UIControl, UIControl inherits from UIView, UIView inherits from UIResponder, UIResponder inherits from the root class NSObject

9- What is dynamic?

You use the @dynamic keyword to tell the compiler that you will fulfill the API contract implied by a property either by providing method implementations directly or at runtime using other mechanisms such as dynamic loading of code or dynamic method resolution. It suppresses the warnings that the compiler would otherwise generate if it can’t find suitable implementations. You should use it only if you know that the methods will be available at runtime

 

10-If I call performSelector:withObject:afterDelay: – is the object retained?

Yes, the object is retained. It creates a timer that calls a selector on the current threads run loop. It may not be 100% precise time-wise as it attempts to dequeue the message from
the run loop and perform the selector.

  • Click to share on Reddit (Opens in new window)
  • Click to share on Facebook (Opens in new window)
  • Click to share on Twitter (Opens in new window)
  • Click to share on LinkedIn (Opens in new window)
  • Click to share on Tumblr (Opens in new window)
  • Click to share on Pocket (Opens in new window)
  • Click to share on Pinterest (Opens in new window)
Written by Ranjan - 1019 Views
Tags | API, Interview Questions
AUTHOR
Ranjan

I m Ranjan and Sharing my years of experience in Software Development. Love to code in Mobile apps (IOS, Android, Power Apps, Xamarin, Flutter), Machine Learning ( Beginner ), Dot Net, Databases ( SQL Server, MySql, SQLite), WordPress, Cloud Computing ( AWS, Azure, Google, MongoDB) and many more as required on project-specific. Besides this love to travel and cook.

You Might Also Like

IOS7 Logo

iphone Interview Questions part-9

June 1, 2013
IOS7 Logo

iphone Interview Questions part-6

June 1, 2013
IOS7 Logo

iphone Interview Questions part-7

June 1, 2013
Next Post
Previous Post

Subscribe for updates

Join 6,915 other subscribers

whiteboard

Whiteboard(PRO)

whiteboard

Whiteboard(lite)

alphabets

Kids Alphabet

techlynk

Techlynk

techbyte

Do2Day

techbyte

Techbyte

Latest Posts

  • YT-Featured-Algorithm
    What is Algorithm?
  • Frameworks of IOS
    Frameworks of IOS – Part ( I )
  • NSFileManager or NSPathUtilities
    NSFileManager or NSPathUtilities in Objective-C
  • Passing data between view controllers in Objective-C
    Passing data between view controllers in Objective-C
  • structures-classes-enum
    Structures and Classes in swift !
  • control-system-swift
    Control Flow in Swift
  • swift-concurrency-await
    Concurrency in Swift
  • time-complexity-dsa
    The Term Time Complexity in DSA
  • objective-c-datatypes1
    Objective-C Data Types
  • Convert-jpeg-word
    Convert JPG to Word – Tips You Should Try!

Quick Links

  • #about
  • #myapps
  • #contact
  • #privacy

Other Websites

  • #myQuestions
  • #myBhojanalaya
  • #gadgetFacts
  • #ifscCodesDB

Tag Cloud

Algorithm Android Android Studio API APP Programming Apps blogging Browser Config CSS DATABASE dsa ecommerce error Features Google IO HTML HTML5 IDE installation Interview Questions IOS iPhone javascript Mac objective-c OneDrive OS Placeholder Programming quicktips SDK SEO Settings SMO SQL swift swiftUI Teams Tips & Tricks Tools UI Web Wordpress Xcode

©mycodetips.com