isUpperCase

import kotlin.test.*
import java.util.*

fun main(args: Array<String>) {
//sampleStart
val chars = listOf('A', 'Ψ', 'a', '1', '+')
val (upperCases, notUpperCases) = chars.partition { it.isUpperCase() }
println(upperCases) // [A, Ψ]
println(notUpperCases) // [a, 1, +]
//sampleEnd
}