for
val numbers = arrayOf(1, 2, 3)
for (n in numbers) {
println(n)
}
for (i in numbers.indices) {
println(numbers[i])
}
for ((i, value) in numbers.withIndex()) {
check(numbers[i] == value)
}
// 0 <= i < numbers.size
for (i in 0 until numbers.size) {
println(numbers[i])
}
// forEach
val a = arrayOf(1, 2, 3)
a.forEach(::println)