android - How to return multiple values from a function in Kotlin like we do in Swift?

Question

How to return 3 separate data values of the same type (Int) from a function in Kotlin?

I'm attempting to return the time of day, I need to return the Hour, Minute and Second as separate integers, but all in one go from the same function, is this possible?

In swift we do it like following,

func getTime() -> (Int, Int, Int) {
    ...
    return ( hour, minute, second)
}

can we achieve this in Kotlin?

P.S: I know I can use Array or Hashmap for this but I want to know if there exists something in Kotlin like it is in Swift.

Answer 1

You can't create arbitrary tuples in Kotlin, instead, you can use data classes. One option is using the built in Pair and Triple classes that are generic and can hold two or three values, respectively. You can use these combined with destructuring declarations like this:

fun getPair() = Pair(1, "foo")

val (num, str) = getPair()

You can also destructure a List or Array, for up to the first 5 elements:

fun getList() = listOf(1, 2, 3, 4, 5)

val (a, b, c, d, e) = getList()

The most idiomatic way however would be to define your own data class, which allows you to return a meaningful type from your function:

data class Time(val hour: Int, val minute: Int, val second: Int)

fun getTime(): Time {
    ...
    return Time(hour, minute, second)
}

val (hour, minute, second) = getTime()