Whether seeking in-office or professional iOS developer jobs, you must answer some problematic advanced iOS developer interview questions. According to Apple, there are over 30 million authorized iOS developers, which might lead to tremendous rivalry.

The probable future of iOS app developers is bright as the number of iOS users grows. iOS and Apple’s dedicated customer base have resulted in breakthrough items like the Apple Watch and Apple TV. There is no better moment to become a developer for iOS. If you want to get into mobile application development, anticipate no further.

If you’re a Swift developer practicing for an upcoming employment interview, this article is for you: we’ve compiled a list of the top iOS or Swift interview questions for 2024.

Continue reading and exploring to learn about the top 20 iOS engineer interview questions that will make you a valuable worker in any organization.

Who is an IOS Developer?

An iOS developer creates apps for the iPhone, iPad, and other mobile devices using the iPhone’s operating system (iOS). These programs, or apps, can be classified into various areas, including productivity, business, social networking, and gaming.

Developers understand how iOS works on various Apple devices, including the iPad, the Apple Watch, and iPhone. iOS developers create, test, and refine applications to meet the requirements of their clients. Typically, iOS apps originate using one of the following programming languages: Swift or Objective-C.

Many iOS developers work remotely, while work-from-home options vary per firm. iOS developer jobs may work in various sectors because most rely on apps for customer service or product support. However, technology, finance, and retailing are the top businesses hiring iOS developers.

Top IOS Developer Interview Questions & Answers

If you want to be sure of your setup, here is a collection of professional iOS developer interview questions and answers to assist you in preparing for various IOS developer jobs.

What Are The Objective-C Categories?

Classes in Objective-C allow you to add features to an object without changing it or using subclassing. This keeps the main class short while allowing all necessary methods and attributes to be easily accessible.

If you want to take your response to this interview question further, you can outline a fictitious category and how it would look when implemented. Alternatively, you may highlight a recent project that utilized categories, enabling you to provide a concrete example.

Identify Four Key Data Types Present In Objective-C

The four data types that your developer should be aware of are as follows:

• NSString: Represents a string of characters.
• CGfloat: Denotes the floating point value.
• NSInteger: Specifies an integer.
• BOOL: Denotes a boolean.

Also Read: 32 Frequently Asked Front-End Developer Interview Questions in 2023

How Do You Control Memory In Swift?

Automatic Reference Counting (ARC) is a method to monitor app memory utilization when writing in Swift. The underlying mechanism reduces the requirement for direct or manually managing memory since ARC frees space accessed by class instances when no longer necessary. To boost its efficacy, ARC may require information about the code’s linkages and dependencies.

How Much Expertise Do You Have Testing Voiceover?

VoiceOver is such an essential aspect of Apple’s accessibility system that if your program isn’t compatible with VoiceOver, it’s unlikely to be compatible with other accessibility mechanisms in iOS. So, discuss your experience testing it out, how you ensure you’ve adequately tested the user interface, any issues you encountered, and, for extra points, including the screen curtain!

What is MVC? Tell Me About Its Implementation in iOS

This interview question has appeared in multiple IOS developer job recruitment globally.  MVC, or Model View Controller, is a type of pattern that specifies how functionality ought to be separate when the user interface is developed. In iOS, UI View is the fundamental class that Apple provides for all views. At the same time, UIViewController has an implementation to support the Controller class, which responds to events in a View & updates it as data changes.

Also Read: Coding Careers: Top 5 Interview Questions and Expert Answers

Which JSON Framework does IOS (iPhone OS) Support?

IOS enables the SBJson framework. It is a JSON parser and producer for Objective-C (the primary programming language used when developing apps for OS X and iOS). It combines the programming language C, which includes object-oriented features and a dynamic runtime.

SBJson offers broad APIs and extra control, making JSON processing simple.

What Are The Most Frequent Design Patterns Suggested for iOS Apps?

Delegate, MVC, Observer, & Singleton are among the “core competency” design patterns that Apple recommends for iOS apps.

This is one of the most often asked IOS interview questions for experienced iOS developer applicants, and it provides a unique chance for job seekers. When answering this interview question, go beyond an essential list and offer examples of when you’ve used various design patterns. It will make you appear more qualified. It has the potential to create many IOS developer jobs by 2024.

What’s The Difference Between Synchronous And Asynchronous Tasks?

Synchronous may additionally be described as “in order.” When you conduct a synchronous operation, everything that follows requires waiting for the operation to finish before continuing.

In contrast, “asynchronous” means “out of order.” When you accomplish anything asynchronously, you can execute the following code immediately, and the asynchronous action will occur later. It might execute on a different thread from the remaining portions of the code. It may be repeated on the same topic at another time, and you will be notified when it is completed.

What do you mean by a category? When is it utilized?

A category is a means to add more methods to a class while extending it. It serves to extend the Cocoa Frameworks’ built-in classes with a set of related and extra methods.

What Is The Distinction Between A ‘Bundle ID’ Vs A ‘App ID’?

Each app is defined by its bundle ID, which is set in Xcode. A single project might have several aims and produce several apps. It is exclusive in various ways and comes in free/lite and full/professional editions.

App IDs recognize one or more apps created by a single team of programmers. It is a two-part expression with a period (.) between the Team ID and the bundle IF query string. The bundle ID search string appears by the developer, whereas Apple provides the Team ID.

What Do You Mean By IBeacons?

Apple’s iBeacon technology protocol enables mobile apps to listen for indicators from beacons and respond accordingly. This technology allows mobile apps to recognize their position and provide hyper-contextual data to users according to their location. The base technology is Low Energy Bluetooth. This is also a very important question for IOS developer jobs interview.

Mention A Few Important Aspects Of The Ios Platform

The iOS platform’s primary characteristics include the following:

• Multitasking capabilities
• iCloud allows you to store information in the cloud that you can view from any Apple device logged in with your ID.
• iOS is an encrypted platform; thus, developers cannot access the original code of Apple’s apps.
• Integrates well with other Apple devices 

Why Does Immutability Matter?

Immutability is built into Swift, so Xcode cautions that it was an option if var was set when let. It’s significant because it’s similar to a programming contract: we’re stating This Thing Should Not be modified, and if we try to change it, the compiler’s compiler will reject it.

What’s The Difference Between Keeping And Copying?

Retaining an item increases the retain count with one. The memory stores the object instance until the retain count reaches 0. It saves and shares a reference to that instance with everyone who has kept it. Meanwhile, a copy indicates that the object will eventually clone with identical values but will not share with others.

Also Read: Computer Programming Jobs: Common Interview Questions and How to Answer Them

What Version Control System Are You Using?

When asked questions like these during an executive iOS interview, there isn’t a single correct response. Instead, utilize your experience and professional history to describe which version control systems you use the most.

Because you may have used various solutions over your career, it is a good idea to address each regularly. Furthermore, if you can discuss use cases and offer examples, your response will be more convincing.

When answering this interview question, you should, at the very least, mention any time you utilized Git at work. It’s standard practice to use it for iOS programming. This is a fundamental question for IOS developer jobs. As a consequence, by the time you reach senior level, you ought to possess some understanding of it.

What Are Some Frequent Ios Execution States?

The typical execution states are below:

• Not running: The program is turned off, and no code is being performed.
• Inactive: The app is consecutively running in the foreground and not getting any events.
• Active: The application is now operating in the forefront and receiving events.
• Background: The program is running code in the background.
• Suspended: The program runs in the background but does not execute code.

Also Read: Top 8 IOS App Development Trends You Must Aware in 2023

What’s The Distinction Between KVC And KVO?

KVC (Key-Value Coding) is a way of accessing an object’s properties utilizing strings at execution rather than having to know the attribute names statically during construction.

KVO (Key-Value Observing) enables an application controller or class to track changes in an attribute value. In KVO, an object can request to be alerted of any changes to a specific property, and the observer is immediately alerted if its value changes.

What Is A Protocol, And How Do You Define It?

Like an interface in Java, the protocol specifies a set of optional and necessary methods that a class can or must implement to use the protocol. Any class can create a protocol; other classes may transmit protocol method-based communications to the class regardless of its nature.

What Is GCD?

GCD signifies Grand Central Dispatch. It serves as a low-level API for managing numerous concurrent operations. It will help you improve the adaptability of your app by offloading computationally heavy activities to the surroundings. It’s a more straightforward concurrency approach than locks and threads.

How Can You Lower The Size Of The App?

It is the last but important question for various IOS developer jobs in 2024. There are three primary approaches for reducing app size:

• Bit code
• On-demand Resources
• Application Slicing

Conclusion

Above, we’ve discussed the top 20 IOS interview questions and their answers. We are 100% sure these questions are fundamental for different IOS developer jobs in 2024. As an iOS developer, you ought to keep up with developments in the iOS ecosystem. Follow Apple development news, read blogs, attend podcasts, and be open to learning new things. You may not be asked about this, but it helps you stand out during an interview. If you have any questions about IOS developer jobs or you want us to add more IOS developer interview questions and answers, please don’t hesitate to comment down your concerns.