Slow range forEach in Kotlin

Question

I used the following code to measure performance of different syntax constructions in Kotlin

fun time(what: String, body: () -> Int) {
    val start =          


        

Answer 1

Thanks for this code. I was more interested in the performance difference between array and list and was a bit shocked to have 6 times as long running time. I thought the list is only slow in creation.

Above runtimes on my machine or comparison: for in range: 55
for in collection: 57
forEach: 55
range forEach: 223
sum: 57

//code change
//val arr = IntArray(n) { rand.nextInt() }
val arr = List(n) { rand.nextInt() }

for in range: 383
for in collection: 367
forEach: 367
range forEach: 486
sum: 371