Cognizant IOS Developer Interview Questions and Answers

Q1. Arc in swift...
Ans. 
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
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Q2. Automstic referenc counting
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Q1. Mvvm in swift....
Ans. 
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
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Q2. Model view viewmodel
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Q1. Tell me about your self
Ans. 
I am an experienced IOS Developer with a passion for creating innovative and user-friendly mobile applications.
• Over 5 years of experience in IOS app development

• Proficient in Swift and Objective-C programming languages

• Strong understanding of mobile UI/UX design principles

• Familiar with RESTful APIs and third-party libraries

• Developed and launched multiple successful IOS apps, such as XYZ and ABC
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Q1. Basic ios questions
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Q2. Difference between let and var
Ans. 
let is used for constants that do not change, var is used for variables that can change
• let is used for constants that do not change

• var is used for variables that can change

• let variables cannot be reassigned once they are set

• var variables can be reassigned multiple times
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Q1. Basic Swift and Objective c
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Q2. Deep into iOS Swift and Objective C
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Q1. Deep in Development and Coding test
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Q2. Management related questions
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Q1. How do you manage local data?
Ans. 
Local data is managed using Core Data framework in iOS development.
• Use Core Data framework to create, read, update, and delete local data.

• Utilize entities, attributes, and relationships to model the data.

• Implement fetch requests to retrieve data based on specific criteria.

• Use NSManagedObject subclasses to represent data objects.

• Utilize NSPersistentContainer to manage the Core Data stack.
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Q2. How can you create dynamic UI like amazon?
Ans. 
Dynamic UI like Amazon can be created using a combination of responsive design, data-driven content, and user personalization.
• Utilize responsive design principles to ensure the UI adapts to different screen sizes and devices.

• Implement data-driven content to display relevant information based on user preferences and behavior.

• Use user personalization techniques such as recommendations, personalized product suggestions, a...read more
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Q1. Encription and decription in swift
Ans. 
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.
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Q2. Keychain access in swift
Ans. 
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.
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Q3. Class vs struct
Ans. 
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
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Q4. If let and guard let
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Q5. Grand central dispatch in swift
Ans. 
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.
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Q1. Basic interview swift questions (medium to hard)
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Q2. Coding to find correct or whats wrong
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Machine test with collection view and api using url session

Q1. Technical questions of different scenarios
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Q1. Objective C vs swift
Ans. 
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
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Q2. Autolayouts and content
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