incrementAndFetchAt   
  Atomically increments the element of this AtomicIntArray at the given index by one and returns the new value of the element.
Since Kotlin
2.1Throws
if the index is out of bounds of this array.
Samples
import kotlin.concurrent.atomics.*
fun main() { 
   //sampleStart 
   val a = AtomicIntArray(intArrayOf(1, 2, 3))
println(a.incrementAndFetchAt(1)) // 3
println(a.loadAt(1)) // 3
println(a.toString()) // [1, 3, 3] 
   //sampleEnd
}Atomically increments the element of this AtomicLongArray at the given index by one and returns the new value of the element.
Since Kotlin
2.1Throws
if the index is out of bounds of this array.
Samples
import kotlin.concurrent.atomics.*
fun main() { 
   //sampleStart 
   val a = AtomicLongArray(longArrayOf(1, 2, 3))
println(a.incrementAndFetchAt(1)) // 3
println(a.loadAt(1)) // 3
println(a.toString()) // [1, 3, 3] 
   //sampleEnd
}