maybe

val frameDurationArray = IntArray(frames + 1) { animation?.getDuration(it)!! }
val duration = frameDurationArray.sum()

Interesting, I can easily use

reduce

by creating an Array like you do… Thanks!

strange, I can call reduce on a range, as ranges are Iterable and reduce is defined for Iterable

@drako You are right. I missed the last one here: https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/reduce.html Still, I am not sure why

reduce

did not appear in AS auto-complete. Perhaps I did not put my range inside parentheses.