kotlin-stdlib/kotlin.collections/MutableSet/retainAll

retainAll

expect abstract override fun retainAll(elements: Collection<E>): Boolean(source)

Retains only the elements in this collection that are contained in the specified collection.

Since Kotlin

1.0

Return

true if any element was removed from the collection, false if the collection was not modified.

Samples

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

fun main() { 
   //sampleStart 
   val collection: MutableCollection<Char> = mutableSetOf('a', 'b', 'c')

// Nothing was removed
println("collection.retainAll(listOf('a', 'b', 'c')) is ${collection.retainAll(listOf('a', 'b', 'c'))}") // false
println(collection) // [a, b, c]

println("collection.retainAll(listOf('a', 'e', 'i', 'o')) is ${collection.retainAll(listOf('a', 'e', 'i', 'o'))}") // true
println(collection) // [a] 
   //sampleEnd
}
actual abstract override fun retainAll(elements: Collection<E>): Boolean(source)

Retains only the elements in this collection that are contained in the specified collection.

Since Kotlin

1.1

Return

true if any element was removed from the collection, false if the collection was not modified.

Samples

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

fun main() { 
   //sampleStart 
   val collection: MutableCollection<Char> = mutableSetOf('a', 'b', 'c')

// Nothing was removed
println("collection.retainAll(listOf('a', 'b', 'c')) is ${collection.retainAll(listOf('a', 'b', 'c'))}") // false
println(collection) // [a, b, c]

println("collection.retainAll(listOf('a', 'e', 'i', 'o')) is ${collection.retainAll(listOf('a', 'e', 'i', 'o'))}") // true
println(collection) // [a] 
   //sampleEnd
}
actual abstract override fun retainAll(elements: Collection<E>): Boolean(source)

Retains only the elements in this collection that are contained in the specified collection.

Since Kotlin

1.0

Return

true if any element was removed from the collection, false if the collection was not modified.

Samples

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

fun main() { 
   //sampleStart 
   val collection: MutableCollection<Char> = mutableSetOf('a', 'b', 'c')

// Nothing was removed
println("collection.retainAll(listOf('a', 'b', 'c')) is ${collection.retainAll(listOf('a', 'b', 'c'))}") // false
println(collection) // [a, b, c]

println("collection.retainAll(listOf('a', 'e', 'i', 'o')) is ${collection.retainAll(listOf('a', 'e', 'i', 'o'))}") // true
println(collection) // [a] 
   //sampleEnd
}
actual abstract override fun retainAll(elements: Collection<E>): Boolean(source)

Retains only the elements in this collection that are contained in the specified collection.

Since Kotlin

1.3

Return

true if any element was removed from the collection, false if the collection was not modified.

Samples

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

fun main() { 
   //sampleStart 
   val collection: MutableCollection<Char> = mutableSetOf('a', 'b', 'c')

// Nothing was removed
println("collection.retainAll(listOf('a', 'b', 'c')) is ${collection.retainAll(listOf('a', 'b', 'c'))}") // false
println(collection) // [a, b, c]

println("collection.retainAll(listOf('a', 'e', 'i', 'o')) is ${collection.retainAll(listOf('a', 'e', 'i', 'o'))}") // true
println(collection) // [a] 
   //sampleEnd
}
actual abstract override fun retainAll(elements: Collection<E>): Boolean(source)

Retains only the elements in this collection that are contained in the specified collection.

Since Kotlin

1.8

Return

true if any element was removed from the collection, false if the collection was not modified.

Samples

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

fun main() { 
   //sampleStart 
   val collection: MutableCollection<Char> = mutableSetOf('a', 'b', 'c')

// Nothing was removed
println("collection.retainAll(listOf('a', 'b', 'c')) is ${collection.retainAll(listOf('a', 'b', 'c'))}") // false
println(collection) // [a, b, c]

println("collection.retainAll(listOf('a', 'e', 'i', 'o')) is ${collection.retainAll(listOf('a', 'e', 'i', 'o'))}") // true
println(collection) // [a] 
   //sampleEnd
}
actual abstract override fun retainAll(elements: Collection<E>): Boolean(source)

Retains only the elements in this collection that are contained in the specified collection.

Since Kotlin

1.8

Return

true if any element was removed from the collection, false if the collection was not modified.

Samples

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

fun main() { 
   //sampleStart 
   val collection: MutableCollection<Char> = mutableSetOf('a', 'b', 'c')

// Nothing was removed
println("collection.retainAll(listOf('a', 'b', 'c')) is ${collection.retainAll(listOf('a', 'b', 'c'))}") // false
println(collection) // [a, b, c]

println("collection.retainAll(listOf('a', 'e', 'i', 'o')) is ${collection.retainAll(listOf('a', 'e', 'i', 'o'))}") // true
println(collection) // [a] 
   //sampleEnd
}