Kotlin Android Interview Questions — Part 2
Here in this article, I will be sharing some more famous Kotlin Android Interview questions that are asked in Android Interviews. So, if you are preparing for Android Interviews, then this article is a must for you.
For part 1 of the question please go this link
- What are higher-order functions in Kotlin? Provide an example.
Higher-order functions are functions that can accept other functions as parameters or return functions as results. They allow for a more functional programming style in Kotlin. Here’s an example:
fun performOperation(x: Int, y: Int, operation: (Int, Int) -> Int): Int {
return operation(x, y)
}val sum: (Int, Int) -> Int = { a, b -> a + b }
val result = performOperation(5, 3, sum) // result will be 82. Explain the concept of generics in Kotlin. How are generics used in Android development?
Generics in Kotlin allow you to create reusable components that can work with different types. They provide type safety and avoid the need for type casting. Generics are widely used in Android development, for example, when working with collections like List<T> or when creating adapters for RecyclerViews. Here's an example:
fun <T> getListSize(list: List<T>): Int {
return list.size
}
val stringList: List<String> = listOf("A", "B", "C")
val size = getListSize(stringList) // size will be 33. What is the difference between lateinit and lazy initialization in Kotlin?
The lateinit modifier is used to declare a non-null property that will be initialized later before its first use. The lazy function is used to create a property whose value is computed lazily and cached. The main difference is that lateinit is for mutable properties, while lazy is for read-only properties. Here's an example:
lateinit var lateInitializedProperty: String
val lazyInitializedProperty: String by lazy {
"Hello"
}
lateInitializedProperty = "World"
println(lateInitializedProperty) // Output: World
println(lazyInitializedProperty) // Output: Hello4. What is a primary constructor in Kotlin? How is it different from secondary constructors?
A primary constructor is declared in the class header and is part of the class declaration. It can define properties and receive parameters. On the other hand, secondary constructors are additional constructors declared inside the class body. They provide alternative ways to initialize the class. Here’s an example:
class Person(val name: String, val age: Int) {
constructor(name: String) : this(name, 0) {
// Secondary constructor
}
}5. Explain the concept of type inference in Kotlin. How does it help in reducing code verbosity?
Type inference in Kotlin allows the compiler to automatically determine the type of a variable or expression based on its context. It eliminates the need for explicitly declaring the type, reducing code verbosity. Here’s an example:
val number = 42 // The compiler infers the type as Int
val list = listOf(1, 2, 3) // The compiler infers the type as List<Int>6. What are companion objects in Kotlin? How are they different from regular objects?
Companion objects are used to define properties and functions that are related to a class itself rather than its instances. They are declared inside the class and can be accessed using the class name. Companion objects are similar to regular objects, but they have the advantage of being associated with a class and accessing its private members. Here’s an example:
class MyClass {
companion object {
fun create(): MyClass {
// Access private members of MyClass
return MyClass()
}
}
}val instance = MyClass.create()7. How do you handle exceptions in Kotlin? Explain the try-catch-finally block.
In Kotlin, exceptions are handled using the try-catch-finally block. The code that might throw an exception is placed inside the try block. If an exception occurs, it is caught and handled in the catch block. The finally block is optional and is executed regardless of whether an exception occurred. Here’s an example:
try {
// Code that might throw an exception
} catch (e: Exception) {
// Exception handling
} finally {
// Code that will always execute
}8. What are the visibility modifiers available in Kotlin? Explain each one briefly.
Kotlin provides four visibility modifiers:
private: Visible only within the same file.protected: Visible within the same file and subclasses.internal: Visible within the same module.public: Visible everywhere (default if no modifier is specified).
These modifiers control the visibility and accessibility of classes, functions, properties, and other declarations.
9. What is the difference between a lambda expression and an anonymous function in Kotlin?
Both lambda expressions and anonymous functions allow you to define function literals in Kotlin. The main difference is in the syntax. Lambda expressions are surrounded by curly braces and have implicit return, while anonymous functions have the fun keyword, explicit return types, and can have multiple return statements. Here's an example:
val lambda: (Int, Int) -> Int = { a, b -> a + b }
val anonymousFun = fun(a: Int, b: Int): Int {
return a + b
}I hope these additional questions and answers help you in your Android interview preparation. If you have any more specific questions or need further assistance, feel free to ask!
For more interview question and their answer please visit the below articles
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