Kaizen Infotech IOS Developer Interview Questions and Answers

Questions about basic Swift knowledge and past work experience.

• Basic Swift concepts such as optionals, closures, and protocols may be asked.

• Questions about past projects and how you approached problem-solving may also be asked.

• Examples of past work experience and projects may be requested.

• Questions about Swift syntax and best practices may be asked as well.

Clean coding principles ensure code readability, maintainability, and scalability.

• Use meaningful variable and function names

• Keep functions short and focused

• Avoid code duplication

• Follow SOLID principles

• Write unit tests

• Refactor regularly

diff is used to compare two collections and return the differences, while guard is used for early exit in a function if a condition is not met.

• diff is a method used in Swift to compare two collections and return the differences.

• guard is a keyword used in Swift to provide an early exit from a function if a condition is not met.

• Example: let array1 = [1, 2, 3, 4], array2 = [3, 4, 5, 6]; let result = array1.diff(array2) //...read more

GCD stands for Grand Central Dispatch, a technology used in iOS for managing concurrent operations. Multithreading is the ability of a CPU to execute multiple threads concurrently.

• GCD is used for managing tasks asynchronously and efficiently utilizing system resources.

• Multithreading allows multiple tasks to run concurrently, improving performance and responsiveness of an application.

• Example: Using GCD to download image...read more

Objective-C is the older language used for iOS development, while Swift is the newer, more modern language.

• Objective-C is a superset of C with Smalltalk-style messaging syntax.

• Swift is more concise and easier to read than Objective-C.

• Swift is safer due to its optionals and type interference features.

• Objective-C has been around longer and has a larger codebase, but Swift is becoming more popular.

• Many developers prefer S...read more

Serialisation in API is the process of converting data into a format that can be easily transmitted over a network.

• Serialisation is used to convert complex data structures into a format that can be easily transmitted over a network.

• It involves converting objects or data structures into a stream of bytes that can be sent over a network.

• JSON and XML are commonly used formats for serialising data in APIs.

• Serialisation is ...read more

Codable is a protocol in Swift that allows for easy encoding and decoding of data types to and from external representations.

• Codable protocol is used to convert custom data types to and from external representations such as JSON, plist, etc.

• It requires the types to conform to Encodable and Decodable protocols.

• Codable protocol provides default implementations for encoding and decoding.

• Example: struct Person: Codable { v...read more

MVVM is an architectural design pattern that separates the user interface code from the business logic and data model.

• MVVM stands for Model-View-ViewModel

• Model represents the data and business logic

• View displays the UI elements and interacts with the user

• ViewModel acts as a mediator between the Model and View, handling user inputs and updating the Model

• MVVM helps in achieving separation of concerns and making the code

Classes are reference types, while structs are value types in Swift.

• Classes are reference types, meaning they point to the same instance in memory when assigned to a new variable.

• Structs are value types, meaning they create a new copy when assigned to a new variable.

• Classes support inheritance, while structs do not.

• Classes can have deinitializers, while structs cannot.

• Example: class Person { var name: String } vs struc

I can join within 2 weeks of receiving an offer.

• I can start within 2 weeks of receiving an offer

• I need to give notice at my current job before starting

• I have some personal commitments that I need to wrap up before joining

ARC (Automatic Reference Counting) in Swift is a memory management system used to automatically manage memory allocation and deallocation.

• ARC keeps track of how many references there are to an object and automatically deallocates it when there are no more references.

• Use strong reference cycles can lead to memory leaks, so use weak or unowned references to break the cycle.

• ARC is the default memory management system in S...read more

MVVM (Model-View-ViewModel) is an architectural design pattern commonly used in iOS development to separate concerns and improve code maintainability.

• MVVM separates the user interface (View) from the business logic (ViewModel) and data (Model).

• ViewModel acts as an intermediary between the View and the Model, handling user interactions and updating the data.

• Swift provides tools like Combine framework for reactive progra...read more

Encryption and decryption in Swift involves using cryptographic algorithms to encode and decode data securely.

• Use common encryption algorithms like AES or RSA for encryption.

• Implement encryption using libraries like CommonCrypto or CryptoSwift.

• Store encryption keys securely and use secure protocols for data transmission.

• Example: Encrypting a string using AES encryption in Swift.

Keychain access in Swift allows secure storage of sensitive information like passwords, tokens, etc.

• Use Keychain Services API to securely store and retrieve sensitive data.

• Keychain items are stored securely in the device's keychain and are encrypted.

• Access keychain items using unique identifiers called keys.

• Use Keychain Swift library for easier implementation.

Classes are reference types, while structs are value types in Swift.

• Classes are reference types, meaning they point to the same instance in memory when assigned to a new variable.

• Structs are value types, meaning they create a new copy when assigned to a new variable.

• Use classes for complex data structures or when you need inheritance, use structs for simple data types or when you want value semantics.

• Example: class Per...read more

Grand Central Dispatch (GCD) is a technology in Swift for managing concurrent operations.

• GCD allows developers to perform tasks concurrently without having to manage threads manually.

• It provides a high-level API for managing tasks and executing them on different queues.

• Developers can use GCD to perform tasks in the background, update the UI on the main thread, and more.