Deutsche Telekom IOS Developer Interview Questions and Answers

Q1. Output question on hoisting
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Q2. Custom Reduce method of JS
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Custom reduce method in JavaScript allows for custom logic to be applied when reducing an array.
• Custom reduce method can be implemented using a for loop to iterate over the array elements.

• The custom logic can be defined within the reduce method to perform specific operations on each element.

• The initial value for the accumulator can be provided as an argument to the custom reduce method.

• Example: Implementing a custom re...read more
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Q3. Bracket validation code
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Q4. React Native, Redux concept, Pure Functions, Pure Component vs React.memo, FlatList
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Q1. Programming - print the first and last letter of words from a list alternatively
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Print the first and last letter of words from a list alternatively
• Iterate through the list of words

• For each word, print the first and last letter alternatively
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Q2. What is oop and oops concepts
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OOP stands for Object-Oriented Programming. OOPs concepts are the principles of OOP such as inheritance, encapsulation, polymorphism, and abstraction.
• OOP is a programming paradigm based on the concept of objects, which can contain data in the form of fields and code in the form of procedures.

• OOPs concepts include inheritance, where a class can inherit properties and behavior from another class.

• Encapsulation is the bund...read more
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Mid level coding test

Q1. DSA question like array linked list
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Q1. SOLID Principle
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Q2. Singlton is good or bed
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Q3. Concept of Closure
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Closure is a function that captures variables from its surrounding scope, allowing them to be accessed even after the function has finished executing.
• Closure allows functions to access variables from their parent functions even after the parent functions have finished executing.

• It helps in maintaining state in asynchronous operations.

• Example: A function returning another function that uses variables from the outer func
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Q1. Architecture based Question
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Q2. What is URLSession, Explain with code
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URLSession is a class in iOS that allows you to make network requests and handle responses.
• URLSession is used to create tasks for fetching data from the internet.

• It supports various types of tasks such as data tasks, download tasks, and upload tasks.

• You can configure URLSession with URLSessionConfiguration to customize its behavior.

• Example: URLSession.shared.dataTask(with: url) { (data, response, error) in }
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Q3. What is codable?
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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 formats like JSON, plist, etc.

• It combines Encodable and Decodable protocols, making it easier to work with data serialization and deserialization.

• Example: struct Person: Codable { var name: String }

• Example: let jsonData =
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Q4. Array based program
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Program to manipulate an array of strings
• Use built-in array methods like push, pop, shift, unshift, splice for manipulation

• Iterate through the array using loops like for loop or forEach

• Use array methods like filter, map, reduce for more complex operations
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Q1. What is mvvm how it handle configuration changes ?
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MVVM stands for Model-View-ViewModel, a design pattern that separates the UI from the business logic.
• MVVM separates the UI (View) from the business logic (ViewModel) using a data-binding mechanism.

• ViewModel retains data during configuration changes, ensuring that data is not lost when the device is rotated or the app is put in the background.

• ViewModel survives configuration changes by being retained by the system, whil
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Q2. Android 14 changes?
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Android 14 introduced new features like improved privacy controls, enhanced performance, and updated APIs.
• Improved privacy controls with more granular app permissions

• Enhanced performance optimizations for smoother user experience

• Updated APIs for developers to utilize new functionalities

• Introduction of new security features to protect user data
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Q1. What is mvvm architecture in ios
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MVVM is a design pattern that separates UI code from business logic and data models.
• MVVM stands for Model-View-ViewModel

• Model represents the data and business logic

• View displays the UI and user interactions

• ViewModel acts as a mediator between Model and View

• ViewModel exposes data and commands to View

• MVVM helps in testability, maintainability and scalability of code
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Q2. What is mvc architecture
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MVC is a software architecture pattern that separates an application into three interconnected components: Model, View, and Controller.
• Model represents the data and business logic of the application

• View displays the data to the user and handles user input

• Controller handles user input and updates the model and view accordingly

• MVC promotes separation of concerns and modularity

• Example: iOS app with a login screen - Model ...read more
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Q1. What is mvvm in swift?
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MVVM (Model-View-ViewModel) is a design pattern used in Swift to separate the user interface logic from the business logic.
• MVVM divides the code into three main components: Model, View, and ViewModel.

• Model represents the data and business logic of the application.

• View displays the data and interacts with the user.

• ViewModel acts as a mediator between the Model and View, handling the logic for the View.

• MVVM helps in maki...read more
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Q2. What is multithreading
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Multithreading is the ability of a CPU to execute multiple threads concurrently, allowing for improved performance and responsiveness in applications.
• Multithreading allows multiple tasks to be executed simultaneously on a single CPU core.

• It can improve performance by utilizing idle CPU time for other tasks.

• Examples include running background tasks while the main thread handles user interactions in an iOS app.
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