measureNanoTime

JVM
1.0
inline fun measureNanoTime(block: () -> Unit): Long
(source)
Native
1.3
@DeprecatedSinceKotlin("1.9") inline fun measureNanoTime(
    block: () -> Unit
): Long

(source)
Deprecated: Use measureTime() instead.
For JVM

Executes the given block and returns elapsed time in nanoseconds.

import kotlin.system.*

fun main(args: Array<String>) {
//sampleStart
var sqrt = 0
val number = 1000
val timeInNanos = measureNanoTime {
    while (sqrt * sqrt < number) sqrt++
}
println("(The operation took $timeInNanos ns)")
println("The approximate square root of $number is between ${sqrt - 1} and $sqrt")
//sampleEnd
}
For Native

Executes the given block and returns elapsed time in nanoseconds.

This function is deprecated. To measure the duration of execution of a block of code, use measureTime or measureTimedValue instead. The resulting Duration then can be expressed as a Long number of nanoseconds using Duration.inWholeNanoseconds.

import kotlin.system.*

fun main(args: Array<String>) {
//sampleStart
var sqrt = 0
val number = 1000
val timeInNanos = measureNanoTime {
    while (sqrt * sqrt < number) sqrt++
}
println("(The operation took $timeInNanos ns)")
println("The approximate square root of $number is between ${sqrt - 1} and $sqrt")
//sampleEnd
}