kotlin-stdlib/kotlin.collections/getOrElse

getOrElse

inline fun <T> Array<out T>.getOrElse(index: Int, defaultValue: (Int) -> T): T(source)
inline fun ByteArray.getOrElse(index: Int, defaultValue: (Int) -> Byte): Byte(source)
inline fun ShortArray.getOrElse(index: Int, defaultValue: (Int) -> Short): Short(source)
inline fun IntArray.getOrElse(index: Int, defaultValue: (Int) -> Int): Int(source)
inline fun LongArray.getOrElse(index: Int, defaultValue: (Int) -> Long): Long(source)
inline fun FloatArray.getOrElse(index: Int, defaultValue: (Int) -> Float): Float(source)
inline fun DoubleArray.getOrElse(index: Int, defaultValue: (Int) -> Double): Double(source)
inline fun BooleanArray.getOrElse(index: Int, defaultValue: (Int) -> Boolean): Boolean(source)
inline fun CharArray.getOrElse(index: Int, defaultValue: (Int) -> Char): Char(source)

Returns an element at the given index or the result of calling the defaultValue function if the index is out of bounds of this array.

Since Kotlin

1.0

Samples

import kotlin.test.*

fun main() { 
   //sampleStart 
   val emptyArray: Array<Any> = emptyArray()
println(emptyArray.getOrElse(0) { "default" }) // default

val array = arrayOf(1)
println(array.getOrElse(0) { 0 }) // 1
println(array.getOrElse(-1) { 0 }) // 0
println(array.getOrElse(0) { "default" }) // 1
println(array.getOrElse(-1) { "default" }) // default

// arrays of primitive types
val intArray = intArrayOf(1, 2, 3)
println(intArray.getOrElse(0) { 0 }) // 1
println(intArray.getOrElse(-1) { 0 }) // 0

val booleanArray = booleanArrayOf(true, false)
println(booleanArray.getOrElse(0) { false }) // true
println(booleanArray.getOrElse(-1) { false }) // false

val charArray = charArrayOf('a', 'b', 'c')
println(charArray.getOrElse(0) { 'z' }) // a
println(charArray.getOrElse(-1) { 'z' }) // z

// arrays of unsigned types
val uIntArray = uintArrayOf(1u, 2u, 3u)
println(uIntArray.getOrElse(0) { 10u }) // 1
println(uIntArray.getOrElse(-1) { 10u }) // 10 
   //sampleEnd
}
inline fun <T> List<T>.getOrElse(index: Int, defaultValue: (Int) -> T): T(source)

Returns an element at the given index or the result of calling the defaultValue function if the index is out of bounds of this list.

Since Kotlin

1.0

Samples

import kotlin.math.*
import kotlin.test.*

fun main() { 
   //sampleStart 
   val list = listOf(1, 2, 3)
println(list.getOrElse(0) { 42 }) // 1
println(list.getOrElse(2) { 42 }) // 3
println(list.getOrElse(3) { 42 }) // 42
println(list.getOrElse(-1) { 42 }) // 42

val emptyList = emptyList<Int>()
println(emptyList.getOrElse(0) { "no int" }) // no int 
   //sampleEnd
}
@ExperimentalUnsignedTypes
inline fun UIntArray.getOrElse(index: Int, defaultValue: (Int) -> UInt): UInt(source)
@ExperimentalUnsignedTypes
inline fun ULongArray.getOrElse(index: Int, defaultValue: (Int) -> ULong): ULong(source)
@ExperimentalUnsignedTypes
inline fun UByteArray.getOrElse(index: Int, defaultValue: (Int) -> UByte): UByte(source)
@ExperimentalUnsignedTypes
inline fun UShortArray.getOrElse(index: Int, defaultValue: (Int) -> UShort): UShort(source)

Returns an element at the given index or the result of calling the defaultValue function if the index is out of bounds of this array.

Since Kotlin

1.3

Samples

import kotlin.test.*

fun main() { 
   //sampleStart 
   val emptyArray: Array<Any> = emptyArray()
println(emptyArray.getOrElse(0) { "default" }) // default

val array = arrayOf(1)
println(array.getOrElse(0) { 0 }) // 1
println(array.getOrElse(-1) { 0 }) // 0
println(array.getOrElse(0) { "default" }) // 1
println(array.getOrElse(-1) { "default" }) // default

// arrays of primitive types
val intArray = intArrayOf(1, 2, 3)
println(intArray.getOrElse(0) { 0 }) // 1
println(intArray.getOrElse(-1) { 0 }) // 0

val booleanArray = booleanArrayOf(true, false)
println(booleanArray.getOrElse(0) { false }) // true
println(booleanArray.getOrElse(-1) { false }) // false

val charArray = charArrayOf('a', 'b', 'c')
println(charArray.getOrElse(0) { 'z' }) // a
println(charArray.getOrElse(-1) { 'z' }) // z

// arrays of unsigned types
val uIntArray = uintArrayOf(1u, 2u, 3u)
println(uIntArray.getOrElse(0) { 10u }) // 1
println(uIntArray.getOrElse(-1) { 10u }) // 10 
   //sampleEnd
}
inline fun <K, V> Map<K, V>.getOrElse(key: K, defaultValue: () -> V): V(source)

Returns the value for the given key if the value is present and not null. Otherwise, returns the result of the defaultValue function.

Note: it's not recommended to use this function if the map is expected to contain null values. Use either getOrElseIfNull, or getOrElseIfMissing instead to express the intent what to return when the key is mapped to null value more clearly.

Since Kotlin

1.0

Samples

import kotlin.test.*
import java.util.*

fun main() { 
   //sampleStart 
   val map = mutableMapOf<String, Int?>()
println(map.getOrElse("x") { 1 }) // 1

map["x"] = 3
println(map.getOrElse("x") { 1 }) // 3

map["x"] = null
println(map.getOrElse("x") { 1 }) // 1 
   //sampleEnd
}