如何从 function 返回数组到 Kotlin

Question

Hello i'm trying to return array from my function but i got this in result:

[Ljava.lang.String;@1be6f5c3

but function output correctly, for example:

12, 54, 65

fun main() {
    val array = arrayOf(loopForNumbers(n))
    println(array)
}

fun loopForNumbers(n: Int): String {
    val array = IntArray(n)
    var i = 0
    while (i < n) {
        println("Input number № ${i + 1}")
        array[i] = readLine()?.toIntOrNull() ?: continue
        i++
    }
    println(array.joinToString())
    return array.joinToString()
}

Answer 1

You got confused I think, it's better to return the array as-is and then format it

fun main() {
    val array = loopForNumbers(n)
    println(array.joinToString())
}

fun loopForNumbers(n: Int): IntArray {
    val array = IntArray(n)
    var i = 0
    while (i < n) {
        println("Введите число № ${i + 1}")
        array[i] = readLine()?.toIntOrNull() ?: continue
        i++
    }
    println(array.joinToString())
    return array
}

Answer 2

but function output correctly, for example:

 12, 54, 65

val array = arrayOf(loopForNumbers(n))

This creates a single-element array containing (in this case) the string "12, 54, 65" .

println(array)

println calls toString() on its argument, and for an array toString is pretty useless because it doesn't include the array contents ; [Ljava.lang.String;@1be6f5c3 is a String array and [I@1be6f5c3 is an Int array, but the part after @ just lets you see if two arrays are the same. Instead try

println(array.joinToString())

see https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/join-to-string.html for documentation and optional parameters.