Introduction to iOS Interview Questions And Answers
iOS is one of the most popular mobile operating systems, which is mainly developed for Apple iPhone users. It is created and developed by Apple Inc. It was initially implemented in 2007 for the iPhone but later has been extended to support other Apple iOS devices like iPod Touch and the iPad. The new major versions of iOS are normally released annually via iTunes and over the air also.
Now, if you are looking for a job that is related to iOS, then you need to prepare for the 2021 iOS Interview Questions. It is true that every interview is different as per the different job profiles, but still, to clear the interview, you need to have a good and clear knowledge of iOS artifacts. Here, we have prepared the important Interview Questions and answers which will help you get success in your interview.
Below are the 10 important 2021 iOS Interview Questions and Answers that are frequently asked in an interview. these questions are divided into parts are as follows:
Part 1 – iOS Interview Questions (Basic)
This first part covers basic Interview Questions and Answers.
1. Explain the SpringBoard functionality for iOS?
SpringBoard is basically a standard application that is mainly used to manage the iOS home screen. It is also involved in launching and bootstrapping applications and start-up setting functionalities.
2. Explain a few new features of iOS 11?
This is the most common iOS Interview Questions which is asked in an interview. The new features of iOS 11 are mentioned below:
- In iOS 11, users now have the ability to send money to their friends using the Apple Pay feature.
- In iOS 11, a new App Drawer feature has been introduced by Apple. With the help of this newly redesigned App Drawer feature, users now will be easily able to share the contents through the Message App.
- In iOS 11, Apple has introduced an updated version of Siri with substantial improvements to its previous versions. The new version of Siri will now offer multiple search results, and multiple languages translations support in real-time.
- The newly redesigned control center in iOS 11 will now offer the 3D Touch support functionality.
- In iOS11, users will be able to sync the messaging app across different iOS devices. So, if the user deletes a message through iPhone, then the same will also be deleted from the synced iPad and Mac and vice-versa.
3. Explain the vieDidLoad and viewDidAppear?
In the case of viewDidLoad, this is mainly called when the hierarchy loading process for the view controller has been completed, and the records have been loaded into memory successfully. Developers can override this method to process the extra initialization process on views that were implemented from nib files.
In the case of viewDidAppear, this is mainly called when the animation process, which is involved in the initial view appearance, has been completed. Developers can override this method to implement different tasks which do not interfere with the ongoing animation view process. So, when there is a rapid change in data or view the animation process, then viewDidAppear is normally the favorable method to implement the system functionalities.
4. Explain Completion Handler and Blocks from an iOS perspective?
Blocks are basically a language-level feature that is implemented along with C and C++ languages. These are used to create distinct code segments which can be passed with respect to the methods or functions. These are not restricted to real-time executions and can also be processed at a later time based on the system functionality. It also implements the codes and displays the same in a much cleaner representative way.
Completion Handler is mainly the approach that is used to process the callback functionality using blocks. Among the different parameters implemented in a method, the completion handler should always remain as the last parameter in the list.
5. Explain StoryBoard and Programmatic UIView from an iOS perspective?
In the case of StoryBoard, Developers can create the same along with a view, and after that, other views can be programmatically added to it. These are mainly used for the UI representation in a short time span and based on the corresponding design specification. It is also used to produce the end-to-end visualization of the entire system process. But in the case of a duplicate handling process, StoryBoard implementation becomes difficult to update as per the system functionality.
In the case of Programmatic UIView, it generally possesses a bit longer and tedious approach than StoryBoard. Here it gives the steadier response to the current code and the corresponding views based on the system functionality. It also develops a branch approach to the entre codes present and thus becomes more easily unit testable.
Part 2 –iOS Interview Questions (Advanced)
Let us now have a look at the advanced Interview Questions.
6. What are the different types of iOS states?
The different types of iOS application states are:
- Idle/Not Running State: In this step, the App should remain either idle or is not running state
- Active State: In this step, the App should remain in a moving state and should work as per the user inputs and system functionality.
- In-Active State: In this step, the App should remain inactive, which means it can be executed in the background but should not perform any UI based functionality.
- Suspended State: In this state, the App should remain in suspended mode. Here, the app should not execute any code, and its ongoing execution should remain in exact stop mode.
7. Which property returns initialized objects?
Atomic Properties usually are implemented to receive properly initialized objects.
8. Explain App Id and Bundle ID from an iOS perspective?
This is the advanced iOS Interview Questions asked in an interview. App Id is basically a two parted string. It is mainly used to identify the implementation progress of one or more applications from the concerned development team perspective. In the case of Bundle Id, it is mainly used to specifically identify the single concerned app.
9. Explain reuseIdentifier?
This specific identifier is used to sort group parameters together for the implementation of identical rows in the UITableView artifacts.
10. Explain a few advantages and disadvantages of iOS?
- Easy development with respect to the UI standardization.
- Normally implemented on a standard toolchain.
- Very smooth operating system and thus the quality is normally higher than Android.
- Follows higher approval matrix which leads to rejection of beta versions.
- The size of the apps is normally on a higher side than that of Android OS.
This has been a guide to the List Of iOS Interview Questions and Answers so that the candidate can crackdown on these Interview Questions easily. Here in this post, we have studied top iOS Interview Questions which are often asked in interviews. You may also look at the following articles to learn more –