fun <T> List<T>.asReversed(): List<T>
Returns a reversed read-only view of the original List. All changes made in the original list will be reflected in the reversed one.
import samples.Sample
import samples.assertPrints
fun main(args: Array<String>) {
//sampleStart
val original = mutableListOf('a', 'b', 'c', 'd', 'e')
val originalReadOnly = original as List<Char>
val reversed = originalReadOnly.asReversed()
println(original) // [a, b, c, d, e]
println(reversed) // [e, d, c, b, a]
// changing the original list affects its reversed view
original.add('f')
println(original) // [a, b, c, d, e, f]
println(reversed) // [f, e, d, c, b, a]
original[original.lastIndex] = 'z'
println(original) // [a, b, c, d, e, z]
println(reversed) // [z, e, d, c, b, a]
//sampleEnd
}@JvmName("asReversedMutable") fun <T> MutableList<T>.asReversed(): MutableList<T> Returns a reversed mutable view of the original mutable List. All changes made in the original list will be reflected in the reversed one and vice versa.
import samples.Sample
import samples.assertPrints
fun main(args: Array<String>) {
//sampleStart
val original = mutableListOf(1, 2, 3, 4, 5)
val reversed = original.asReversed()
println(original) // [1, 2, 3, 4, 5]
println(reversed) // [5, 4, 3, 2, 1]
// changing the reversed view affects the original list
reversed.add(0)
println(original) // [0, 1, 2, 3, 4, 5]
println(reversed) // [5, 4, 3, 2, 1, 0]
// changing the original list affects its reversed view
original[2] = -original[2]
println(original) // [0, 1, -2, 3, 4, 5]
println(reversed) // [5, 4, 3, -2, 1, 0]
//sampleEnd
}
© 2010–2018 JetBrains s.r.o.
Licensed under the Apache License, Version 2.0.
https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/as-reversed.html