More Kotlin fundamentals | Android Developers

Which of the following is a valid way to define a data class in Kotlin?

data class Person(val name: String, val age: Int)

class Person(val name: String, val age: Int): data

class Person(val name: String, val age: Int)

data class Person{val name: String, val age: Int}

When using a sealed class, all direct subclasses must be in the same package.

true

false

When using generics, the generic data type goes inside ___.

[]

{}

()

<>

A(n) ___ class is useful when you have a fixed set of values.

enum

sealed

data

inherited

To create a list object that has the ability to change its size, you would call ___.

modifiableListOf()

immutableListOf()

listOf()

mutableListOf()

Which of the following are higher-order functions?

Choose as many answers as you see fit.

map

arrangeBy

filter

forEach

Given the following line of code, which of the following commands will print Blue? (Hint: If you are not sure, try running the code in the Kotlin Playground.)

val colors = listOf("Red", "Green", "Blue")

Choose as many answers as you see fit.

println(colors[2])

println(colors.get(2))

println(colors.contains(2))

println(colors.getOrDefaultValue(index = 2, defaultValue = 10))

The programming concept of a class that has only one instance is called a ___.

Uniqueness

Singleton

Mono-object

Lambda

Which of the following statements is true regarding sets and maps?

A set must contain distinct values and a map’s keys must be distinct.

A set must contain distinct values and a map’s keys can contain duplicates.

A set can contain duplicate values and a map’s values can contain duplicate values.

A set can contain duplicate values and a map’s keys must be distinct.

If you have a variable named records, which is a collection, to determine the number of items it contains, you can call ___.

records.length

records.quantity

len(records)

records.size