10+ IOS Application Developer Interview Questions and Answers

Concurrency in Swift can be handled using Grand Central Dispatch (GCD) and Operation Queues.

• Use GCD to perform tasks concurrently by creating dispatch queues.

• Use Operation Queues to manage and execute multiple operations concurrently.

• Avoid race conditions by using serial queues or synchronization techniques like semaphores or locks.

Find the first occurrence of a given number in a sorted array.

• Use binary search to efficiently find the first occurrence of the number.

• Keep track of the index of the first occurrence as you search through the array.

• Return the index of the first occurrence once found.

iOS app distribution methods include App Store, Ad Hoc, Enterprise, and TestFlight.

• App Store distribution is for public release and requires Apple's review process.

• Ad Hoc distribution allows sharing apps with a limited number of devices.

• Enterprise distribution is for in-house apps within a company.

• TestFlight is for beta testing with external testers before App Store release.

Creating UI/UX design based on figma for iOS application development.

• Understand the design requirements from figma.

• Implement the design using iOS design guidelines.

• Ensure the design is user-friendly and intuitive.

• Test the design on different iOS devices for compatibility.

• Iterate on the design based on feedback.

• Use tools like Sketch or Adobe XD for design implementation.

High order functions are functions that can take other functions as arguments or return functions as results.

• High order functions can be used to create more flexible and reusable code.

• They allow for the composition of functions, making it easier to combine multiple operations.

• Examples of high order functions in iOS development include map, filter, and reduce.

Pagination is handled by dividing data into smaller chunks and loading them as needed.

• Divide data into smaller chunks

• Load data as needed

• Use APIs like UITableView and UICollectionView

• Implement infinite scrolling

• Use page numbers or cursor-based pagination

Find the 2nd largest element in an array of strings.

• Sort the array in descending order

• Access the element at index 1 to get the 2nd largest element

To get the top view of a binary tree, we need to find the nodes that are visible when looking at the tree from the top.

• Start from the root node and assign it a horizontal distance of 0.

• Traverse the tree using a queue and keep track of the horizontal distance of each node.

• For each horizontal distance, only keep the node with the smallest level in the result.

• Repeat the process for left and right child nodes, updating the horizontal distance accordingly.

NotificationCenter is a system that enables communication between different parts of an application.

• NotificationCenter allows components of an application to communicate without having direct references to each other.

• It uses the observer pattern where objects register themselves as observers for specific notifications.

• Notifications can be posted to the NotificationCenter with optional data.

• Observers can then receive and handle these notifications.

• NotificationCenter is commonl...read more

Protocols are a set of rules or guidelines that define a blueprint of methods, properties, and other requirements.

• Protocols are used to define a contract that classes or structs can adopt and conform to.

• They specify a list of methods and properties that must be implemented by conforming types.

• Protocols can be used to achieve polymorphism and code reuse.

• They can be adopted by multiple classes or structs, allowing them to share common behavior.

• Protocols can also be used to defi...read more

A class is a blueprint for creating objects that have properties and methods. A structure is a lightweight version of a class.

• Classes and structures are used to define the properties and behavior of objects in object-oriented programming.

• Classes can be inherited, while structures cannot.

• Classes are reference types, while structures are value types.

• Classes have a deinitializer, while structures do not.

• Examples: Class - UIViewController, Structure - CGPoint