If you want to launch or maintain an app on the Apple Store, you need an iOS developer. An iOS developer is a software engineer who specializes in making apps for the iOS operating system. Only iOS compatible apps can run on an iPhone.
Before you hire an iOS developer, you need to ensure that they know their way around the operating system. They need to understand the platform’s specific ins and outs to be able to program useful and intuitive apps for the operating system.
Even if you are not familiar with iOS development yourself, you can use these questions to gauge how well each candidate understands iOS. Here are the top questions you can ask to ensure that you hire ios developer who knows what they are doing.
- 1 How Well Do You Understand Objective-C and Swift? Can You Explain the Difference Between the Two?
- 1.1 How does Managed object context (NSManagedObjectContext) work in Objective C, and what is its purpose?
- 1.2 Can you name four essential types of data found in Objective-C?
- 1.3 What are some of the more common execution states in iOS?
- 1.4 What Does KVC stand for?
- 1.5 What does KVO stand for?
- 1.6 You have been informed that the new app you have launched is prone to crashing. How do you fix the problem?
- 1.7 How to pass data between view controllers?
- 1.8 Explain Generics in Swift?
- 1.9 How many APIs are there that can be used for battery-efficient location tracking?
- 1.10 Final Thoughts
How Well Do You Understand Objective-C and Swift? Can You Explain the Difference Between the Two?
Swift is a programming language that was launched in 2014. Upon its launch, this programming language was appropriately described as Objective-C without the C. Swift works without maintaining any of the legacy conventions built into the Objective-C language.
As a whole, Swift is a faster programming language than Objective- C. It is also safer, easier to read, and easier to maintain. Swift was explicitly designed to take into account the needs of the modern programming for those who are developing consumer-facing apps.
While comparing Swift and Objective-C, the foremost difference that any programmer notices is the lack of formal support for namespaces in the former. This official support present in Objective-C forces programmers to use two-letter or three-letter prefixes to tell the difference between the two.
Rather than using prominent and straightforward names such as “Array,” “Dictionary,” and “String,” which can be used in Swift, programmers who use Objective-C need to use clunky language such as “NSString, “NSArray,” and “NSDictionary.”
One of the other primary advantages of Swift over Objective – C, is that the former avoids exposing pointers and other “unsafe” accessors when referring to object instances.
Any developer should know that they need to understand both Objective-C and Swift as a successful iOS developer while maintaining a focus on Swift since it is the likely future of iOS apps.
How does Managed object context (NSManagedObjectContext) work in Objective C, and what is its purpose?
Managed object context is there for three reasons, which are lifecycle management, concurrency, and notifications. It helps developers get an object from a persistent store and make necessary amendments before deciding to discard or commit these changes.
A managed object context is a way for the developer to track these modifications and redo or undo any changes.
Can you name four essential types of data found in Objective-C?
Four of the more critical data types are CGFloat, BOOL, NSIntegar, NSString.
What are some of the more common execution states in iOS?
The most common execution states are the following:
- Not Running: The app is entirely off.
- Inactive: The app is running, but there are no events.
- Active: The app is running, and there are events.
- Background: The app is running in the background.
- Suspended: The app is running in the background but is not executing any code.
What Does KVC stand for?
KVC stands for Key-Value Coding. It is a way for an object’s properties to be accessed using strings at runtime. This negates the need for the developer to know property names during the time of development statically.
What does KVO stand for?
KVO stands for Key-Value Observing. It allows a class or a controller to observe any changes to property value. Under KVO, an object can request to be notified of any changes made to a specific property. The object is automatically notified if a change is made.
You have been informed that the new app you have launched is prone to crashing. How do you fix the problem?
This question is meant to gauge the problem-solving abilities of the developer. In this answer, you should look out for the general methodology that the developer would follow to isolate the problem and solve it.
Since there can be a range of possible answers to this question, you need to check if the developer’s response would be a quick and efficient way to solve it.
If something goes wrong with an app, developers follow a general method to fix a bug. The first step would be to find out the iOS version as well as the model and make of the device. Second, the developer needs to gather enough data to recreate the issue.
Thirdly, the developer needs to read the device logs if they are available. After this, you should have an idea of what the issue is. Hence, you can begin to acquire tooling or the process of creating a unit test. Finally, you can start the debugging process.
An excellent answer to this question would include each of the above steps in the correct order. You can also look for specific examples of debugging tools such as ViewMonitor or BugLife.
You could lookout for a solid knowledge of debugging theory. This theory includes concepts on what to do with runtime errors, logical errors, and time errors.
How to pass data between view controllers?
There are three primary views by which data can be passed between view controllers.
These are Segue (Forward), Delegate (Backward), setting variable directly.
Explain Generics in Swift?
Generics creates code that is not specific regarding underlying types of data. Generics is a way to provide optimization to the code. Generics is a way to know the data type that it is going to have.
How many APIs are there that can be used for battery-efficient location tracking?
There are a total of three APIs that can achieve this.
- Significant Location Changes – The location of the tracked device is delivered after every 1-kilometer change in place.
- Region Monitoring – This is the most precise location tracking method after GPS. It provides enter/exit events from regions that are around 100m or more.
- Visit Events – With this you can track Visit events that enter or exit from a place or location.
Finding the right iOS developer can be a demanding challenge, but it is worth it. A good iOS developer can make or break your app. It is always advisable to do your research before going in to interview an iOS developer. You can also look for wordpress developers to help you with content related work.