Blackcoffer Interview Questions and Answers

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

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 }

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 would handle user authentication, View would display the l...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 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 = try JSONEncoder().encode(person)

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 function.