CodeHS Software Development and App Development Accreditations 1 — Questions and Answers
Question 1: Which of the following is the primary programming language used for developing Android apps?
- Swift
- Kotlin (Correct answer)
- JavaScript
- Python
Correct answer: Kotlin
Kotlin is the primary programming language officially supported by Google for developing Android applications. It is a modern, statically typed language that runs on the Java Virtual Machine (JVM) and is fully interoperable with Java. Kotlin offers features like null safety, concise syntax, and coroutines, which enhance developer productivity and lead to more robust Android apps.
Question 2: What is the purpose of the UIViewController class in iOS development?
- To manage the layout and appearance of user interface elements (Correct answer)
- To handle the app's data storage
- To define the app's navigation bar
- To control the interaction between the app and the device hardware
Correct answer: To manage the layout and appearance of user interface elements
The `UIViewController` class in iOS development is a fundamental component responsible for managing a single screen or a portion of an app's user interface. It acts as a controller, coordinating between the app's data (model) and its visual representation (view). `UIViewController` handles events, updates the UI, and manages the lifecycle of its associated view, making it central to building interactive iOS applications.
Question 3: Which of the following is a mobile app development framework for building cross-platform apps using JavaScript?
- React Native (Correct answer)
- SwiftUI
- Xamarin
- Flutter
Correct answer: React Native
React Native is a popular open-source mobile application development framework created by Facebook, which allows developers to build native mobile apps using JavaScript and React. It enables code reuse across iOS and Android platforms from a single codebase, significantly speeding up development. Developers write JavaScript, and React Native compiles it into native UI components, offering a truly native user experience.
Question 4: Which file extension is typically associated with an Android application package?
- .apk (Correct answer)
- .exe
- .dmg
- .ipa
Correct answer: .apk
The `.apk` (Android Application Package) file extension is the standard format for distributing and installing applications on Android devices. An `.apk` file is an archive file that contains all the elements an Android app needs to be installed correctly on a device, including code, resources, assets, certificates, and manifest file. It's essentially the executable file for Android apps.
Question 5: In Xcode, which programming language is primarily used for iOS app development?
- Swift (Correct answer)
- Java
- Kotlin
- Objective-C
Correct answer: Swift
Swift is Apple's powerful and intuitive programming language for building apps across all Apple platforms, including iOS, macOS, watchOS, and tvOS. Developed to be safe, fast, and modern, Swift is the primary language used in Xcode for iOS app development. It has largely replaced Objective-C as the preferred language due to its improved syntax, performance, and safety features.
CodeHS Software Development and App Development Accreditations 1
Which of the following is the primary programming language used for developing Android apps?