Kotlin: How to access field from another class?

Question

package example

class Apple {
    val APPLE_SIZE_KEY: String = "APPLE_SIZE_KEY"
}

Class:

package example

class Store {
     fun buy() {
      val SIZE = Apple.APPLE_SIZE_KEY
    }
}

Error:

'APPLE_SIZE_KEY' has private access in 'example.Apple'

But official documentation describes that if we do not specify any visibility modifier, public is used by default.

Why is above error coming?

Answer 1

If you want this to be a class level property instead of an instance level property, you can use a companion object:

class Apple {
    companion object {
        val APPLE_SIZE_KEY: String = "APPLE_SIZE_KEY"
    }
}

fun useAppleKey() {
    println(Apple.APPLE_SIZE_KEY)
}

What you currently have is an instance property, which you could use like this:

fun useInstanceProperty() {
    val apple = Apple()
    println(apple.APPLE_SIZE_KEY)
}