Start of Kotlin Mobile Development Features Quiz
1. What is Kotlin`s primary role in Android development?
- Kotlin is exclusively for web applications.
- Kotlin serves as a database management tool.
- Kotlin is used only for backend development.
- Kotlin is the primary language for Android development.
2. What are some benefits of using Kotlin for Android development?
- Using Kotlin for Android development benefits from less code, greater readability, fewer common errors, and improved productivity.
- Using Kotlin for Android development results in slower performance and increased memory usage.
- Using Kotlin for Android development makes apps incompatible with other programming languages.
- Using Kotlin for Android development requires more complex syntax and structures compared to Java.
3. How does Kotlin support multiplatform development?
- Kotlin only supports development for Android applications.
- Kotlin Multiplatform allows development for not only Android but also iOS, backend, and web applications.
- Kotlin requires separate codebases for different platforms.
- Kotlin is not compatible with iOS development at all.
4. What is the purpose of coroutines in Kotlin?
- Coroutines create static variables in Kotlin programs.
- Coroutines enable real-time data storage in Kotlin.
- Coroutines help in compiling Kotlin code faster.
- Coroutines allow asynchronous programming in Kotlin.
5. How do coroutines avoid blocking the main thread in Android?
- Coroutines block the main thread while executing tasks.
- Coroutines use only the main thread for all operations.
- Coroutines pause execution until all tasks complete.
- Coroutines run on background threads, keeping the UI responsive.
6. What is the difference between == and === in Kotlin?
- nan
- nan
- nan
- nan
7. How does Kotlin`s lazy-loading feature improve app startup time?
- The lazy-loading feature loads only necessary resources into main memory, reducing startup time and improving app performance.
- The lazy-loading feature preloads all app resources to ensure immediate availability upon launch.
- The lazy-loading feature eliminates the need for network calls, improving startup speed at all times.
- The lazy-loading feature compresses images during the app launch, speeding up loading times.
8. What are some key features of Kotlin that improve code readability and maintainability?
- Only supports Android applications, lacks strong typing, built solely for Java interoperability, and lacks modern language features.
- A limited set of primitive types, no support for functional programming, verbose syntax, and manual memory management.
- Concise and expressive syntax, data classes, null safety, extension functions, smart casts, and lambda expressions.
- Long and complex class declarations, redundant use of semicolons, explicit type declarations for every variable, and global state manipulation.
9. How does Kotlin`s interoperability with Java benefit developers?
- Kotlin`s interoperability with Java makes it impossible to share libraries between them, causing redundancies in code.
- Kotlin`s interoperability with Java prevents the use of Java frameworks, limiting development options for developers.
- Kotlin`s interoperability with Java requires developers to rewrite all Java code in Kotlin, increasing project complexity.
- Kotlin`s interoperability with Java allows developers to use both languages in the same project, making it easier to switch between them and saving development time.
10. What is the entry point for a Kotlin application?
- fun main(){}
- main() = Unit
- entry() = main{}
- fun start(){}
11. How can you display a nullable string`s length in Kotlin?
- println(b.length ?: -1)
- println(b?.length ?: 0)
- printLength(b?.size ?: 0)
- println(b.length ?: `null`)
12. What is the idiomatic way to set a variable to the greatest value between two variables in Kotlin?
13. How do you fill in the blank to display all even numbers from 1 to 10 in Kotlin?
- count in 2..10 step 1
- count in 1..10 step 1
- count in 1..10 step 2
- count in 2..10 step 2
14. What value is printed by `println(set.count())` where `set` is a set of strings?
- 10
- 1
- 0
- 4
15. What is the purpose of extension functions in Kotlin?
- Extension functions are used only for data classes in Kotlin.
- Extension functions allow you to add functionality to existing classes without inheriting from them.
- Extension functions create new classes that modify existing ones.
- Extension functions replace the need for interfaces in Kotlin.
16. How do you use the `invoke` method with a function reference in Kotlin?
- You use it with `invoke(::add, 5, 10)` to call the method.
- You use it with `::add(5, 10)` as a shorthand syntax.
- You use it with `add(5, 10)` to call the function directly.
- You use it with `::add.invoke(5, 10)` where `add` is a function reference.
17. What is the best loop to use in a console app that processes user input and exits if the input is empty?
- while loop
- do-while loop
- for loop
- repeat loop
18. Why can a primitive integer work with a function expecting type Any in Kotlin?
- The integer cannot be used and causes a type error.
- The integer is autoboxed to a Kotlin Int class.
- The integer is converted to a String type automatically.
- The integer is ignored since it is a primitive type.
19. How do you implement push notifications in an Android app using Kotlin coroutines?
- You can implement push notifications by defining static functions for notifications in your app.
- You can implement push notifications by using callbacks to manage notification tasks.
- You can implement push notifications using a synchronous approach for task execution.
- You can implement push notifications using coroutines for asynchronous notification handling.
20. What are some key features of Kotlin that make it ideal for Android app development?
- Key features include global variable usage, lack of type safety, rigid syntax, manual memory management, and no support for data classes.
- Key features include complex syntax, mandatory exceptions, limited access, static typing, and immediate loading.
- Key features include null safety, unchecked exceptions, property access, smart casts, and lazy loading.
- Key features include error-prone type casting, verbose code, no support for lambda expressions, and single-threaded execution.
21. How do you specify where coroutines should run in Kotlin?
- You specify where coroutines should run using `runBlocking` to block the current thread.
- You specify where coroutines should run using `async` to create a new coroutine automatically.
- You specify where coroutines should run using `ExecutorService` for thread management.
- You specify where coroutines should run using dispatchers like `Dispatchers.Main` for the main thread or `Dispatchers.IO` for I/O operations.
22. What is the difference between declaring a variable with `val` and `var` in Kotlin?
- `val` is for mutable variables, while `var` is for constants.
- Both `val` and `var` are used for read-only variables.
- `var` declares a constant, while `val` allows changes.
- `val` declares a read-only variable, while `var` declares a mutable variable.
23. How do you handle asynchronous tasks in an Android app using Kotlin coroutines?
- You handle asynchronous tasks by using threads directly, which can complicate code and lead to potential issues with synchronization.
- You handle asynchronous tasks by using coroutines, which allow you to write sequential code that is simple and easy to read, avoiding the need for callbacks and improving app performance.
- You handle asynchronous tasks by using nested callbacks, creating deeply nested structures that are hard to manage.
- You handle asynchronous tasks by blocking the main thread, which can cause the app to freeze and become unresponsive.
24. What is the purpose of data classes in Kotlin?
- Data classes are used for defining asynchronous functions in Kotlin.
- Data classes prevent the creation of mutable variables in Kotlin.
- Data classes provide a concise way to create classes that mainly hold data.
- Data classes are used for handling user interface elements in Android.
25. How do you use the `let` function in Kotlin to handle nullable values?
- You utilize it by doing `x?.also { println(x) }` for accessing nullable values safely.
- You use it with `x?.let { println(it) }` to handle nullable values and avoid null pointer exceptions.
- You apply it by writing `if (x != null) { println(x) }` for safe value handling.
- You can use `x?.run { println(this) }` to avoid null pointer issues in values.
26. What is the idiomatic way to check if a string is not null before accessing its length in Kotlin?
- val len = x.length ?: 0
- val len = x?.length ?: -1
- val len = x.length
- val len = if (x != null) x.length else 0
27. How do you declare a primary constructor in a Kotlin class?
- You declare it with `fun constructor(parameters)`.
- You declare it with `class(parameters)`.
- You declare it with `constructor(parameters)` inside the class definition.
- You declare it with `init(parameters)`.
28. What is the purpose of companion objects in Kotlin?
- Companion objects provide functionality shared among instances.
- Companion objects serve as database connections.
- Companion objects are used for creating UI elements.
- Companion objects store instance-specific data.
29. How do you use operator overloading in Kotlin to define custom operators for a class?
- You use it by creating new classes for each operator, like `class PlusOperator`.
- You use it by defining custom operators inside the class, such as `operator fun plus(other: Int): Int { return this + other }`.
- You use it by writing a separate function for each operator without using `operator`.
- You use it by declaring variables of type `operator`, such as `var operator = 10`.
30. What is the purpose of smart casts in Kotlin?
- Smart casts allow for type inference without explicit casting.
- Smart casts improve memory management in Kotlin.
- Smart casts are used for managing application state.
- Smart casts enforce strict typing rules during compilation.
