Kotlin static methods and variables

Question

I want to be able to save a class instance to a public static variable but I can\'t figure out how to do this in Kotlin.

class Foo {

    public static Foo i         


        

Answer 1

You can create a companion object for the class, and if you want the field to be static you can use the annotation @JvmStatic. Companion object have access to private members of the class it is companion for.

See below an example:

class User {
    private lateinit var name: String

    override fun toString() = name

    companion object {
        @JvmStatic
        val instance by lazy {
            User().apply { name = "jtonic" }
        }
    }
}

class CompanionTest {

    @Test
    fun `test companion object`() {
        User.instance.toString() shouldBe "jtonic"
    }
}