Can't use Destructuring declaration

Question

I have a class Person:

class Person(val name: String, val age: Int)

I want to use Destructuring declaration with Parent like this:

val (name, age) = Person("name", 22)

but I get this error:

Destructuring declaration initializer of type Person must have a 'component1()' function Destructuring declaration initializer of type Person must have a 'component2()' function

Answer 1

The easiest way to solve this problem is to use a data class since data classes automatically declare componentN() functions (see the docs).

data class Person(val name: String, val age: Int)
val (name, age) = Person("name", 22) // OK

Sometimes you might not have access to the source code of a class you want to allow destructuring, so if for any reasons you are not allowed to use data classes, you can provide the componentX functions (component1 and component2 in this case) by using extension functions.

operator fun Person.component1() = name
operator fun Person.component2() = age

Answer 2

We need to declare Person as data class.

data class Person(val name: String, val age: Int)

it wasn't very clear in the docs but for official ref:

https://kotlinlang.org/docs/reference/multi-declarations.html#example-returning-two-values-from-a-function

from Marko Topolnik comment:
if for some reason someone can't use data class it's not mandatory. You can declare the functions component1() and component2() in any class.